[1,2,4]Triazolo[4,3-A]pyridinyl substituted indole compounds

ABSTRACT

Disclosed are compounds of Formula (I) or a salt thereof, wherein R1, R2, R3, R4a, R4b, R4c, R4d, R5, n, and p are defined herein. Also disclosed are methods of using such compounds as inhibitors of signaling through Toll-like receptor 7, or 8, or 9, and pharmaceutical compositions comprising such compounds. These compounds are useful in treating inflammatory and autoimmune diseases.

This application is a national phase application under 35 U.S.C. § 371 of International Patent Application No. PCT/US2018/045080, filed Aug. 3, 2018, which claims priority to U.S. Provisional Application Serial No. 62/541,331, filed Aug. 4, 2017, the contents of which are specifically incorporated fully herein by reference.

The present invention generally relates to [1,2,4]triazolo[4,3-a]pyridinyl substituted indole compounds useful as inhibitors of signaling through Toll-like receptor 7, 8, or 9 (TLR7, TLR8, TLR9) or combinations thereof. Provided herein are [1,2,4]triazolo[4,3-A]pyridinyl substituted indole compounds, compositions comprising such compounds, and methods of their use. The invention further pertains to pharmaceutical compositions containing at least one compound according to the invention that are useful for the treatment of conditions related to TLR modulation, such as inflammatory and autoimmune diseases, and methods of inhibiting the activity of TLRs in a mammal.

Toll/IL-1 receptor family members are important regulators of inflammation and host resistance. The Toll-like receptor family recognizes molecular patterns derived from infectious organisms including bacteria, fungi, parasites, and viruses (reviewed in Kawai, T. et al., Nature Immunol., 11:373-384 (2010)). Ligand binding to the receptor induces dimerization and recruitment of adaptor molecules to a conserved cytoplasmic motif in the receptor termed the Toll/IL-1 receptor (TIR) domain. With the exception of TLR3, all TLRs recruit the adaptor molecule MyD88. The IL-1 receptor family also contains a cytoplasmic TIR motif and recruits MyD88 upon ligand binding (reviewed in Sims, J. E. et al., Nature Rev. Immunol., 10:89-102 (2010)).

Toll-like receptors (TLRs) are a family of evolutionarily conserved, transmembrane innate immune receptors that participate in the first-line defense. As pattern recognition receptors, the TLRs protect against foreign molecules, activated by pathogen associated molecular patterns (PAMPs), or from damaged tissue, activated by danger associated molecular patterns (DAMPs). A total of 13 TLR family members have been identified, 10 in human, that span either the cell surface or the endosomal compartment. TLR7-9 are among the set that are endosomally located and respond to single-stranded RNA (TLR7and TLR8) or unmethylated single-stranded DNA containing cytosine-phosphate-guanine (CpG) motifs (TLR9).

Activation of TLR7/8/9 can initiate a variety of inflammatory responses (cytokine production, B cell activation and IgG production, Type I interferon response). In the case of autoimmune disorders, the aberrant sustained activation of TLR7/8/9 leads to worsening of disease states. Whereas overexpression of TLR7 in mice has been shown to exacerbate autoimmune disease, knockout of TLR7 in mice was found to be protective against disease in lupus-prone MRL/lpr mice. Dual knockout of TLR7 and 9 showed further enhanced protection.

As numerous conditions may benefit by treatment involving modulation of cytokines, IFN production and B cell activity, it is immediately apparent that new compounds capable of modulating TLR7 and/or TLR8 and/or TLR9 and methods of using these compounds could provide substantial therapeutic benefits to a wide variety of patients.

The present invention relates to a new class of [1,2,4]triazolo[4,3-a]pyridinyl substituted indole compounds found to be effective inhibitors of signaling through TLR7/8/9. These compounds are provided to be useful as pharmaceuticals with desirable stability, bioavailability, therapeutic index, and toxicity values that are important to their drugability.

SUMMARY OF THE INVENTION

The present invention provides compounds of Formula (I) that are useful as inhibitors of signaling through Toll-like receptor 7, 8, or 9 and are useful for the treatment of proliferative diseases, allergic diseases, autoimmune diseases and inflammatory diseases, or stereoisomers, tautomers, pharmaceutically acceptable salts, solvates or prodrugs thereof.

The present invention also provides pharmaceutical compositions comprising a pharmaceutically acceptable carrier and at least one of the compounds of the present invention or stereoisomers, tautomers, pharmaceutically acceptable salts, solvates, or prodrugs thereof.

The present invention also provides a method for inhibition of Toll-like receptor 7, 8, or 9 comprising administering to a host in need of such treatment a therapeutically effective amount of at least one of the compounds of the present invention or stereoisomers, tautomers, pharmaceutically acceptable salts, solvates, or prodrugs thereof.

The present invention also provides a method for treating proliferative, metabolic, allergic, autoimmune and inflammatory diseases, comprising administering to a host in need of such treatment a therapeutically effective amount of at least one of the compounds of the present invention or stereoisomers, tautomers, pharmaceutically acceptable salts, solvates, or prodrugs thereof.

The present invention provides a method for treating inflammatory and autoimmune diseases. Particular, inflammatory and autoimmune diseases include, but are not limited to, Crohn's disease, ulcerative colitis, asthma, graft versus host disease, allograft rejection, chronic obstructive pulmonary disease, rheumatoid arthritis, systemic lupus erythematosus, lupus nephritis, cutaneous lupus, psoriasis, adult onset Still's disease, systemic onset juvenile idiopathic arthritis, multiple sclerosis.

DETAILED DESCRIPTION

The first aspect of the present invention provides at least one compound of Formula (I):

-   or a salt thereof, wherein: -   R₁ is H, Cl, —CN, C₁₋₄ alkyl, C₁₋₃ fluoroalkyl, C₁₋₃     hydroxy-fluoroalkyl, —CR_(z)═CH₂, C₃₋₆ cycloalkyl, —CH₂(C₃₋₆     cycloalkyl), —C(O)O(C₁₋₃ alkyl), or tetrahydropyranyl; -   each R₂ is independently halo, —CN, —OH, —NO₂ ⁺, C₁₋₃ alkyl, C₁₋₂     fluoroalkyl, C₁₋₃ hydroxyalkyl, C₁₋₃ aminoalkyl, —(CH₂)₀₋₄O(C₁₋₃     alkyl), C₁₋₃ fluoroalkoxy, C₂₋₄ alkoxyalkoxy, —O(CH₂)₁₋₂NR_(x)R_(x),     —C(O)O(C₁₋₃ alkyl), —C(O)NR_(y)R_(y), —NR_(y)R_(y), —NR_(x)C(O)(C₁₋₃     alkyl), —NR_(x)(CH₂-cyclopropyl), C₃₋₆ cycloalkyl,     methylpiperidinyl, methylpiperazinyl, amino-oxadiazolyl, imidazolyl,     triazolyl, or —C(O)(thiazolyl); -   R₃ is:     -   (a) -L₁-A; or     -   (b) H, C₁₋₆ alkyl, C₁₋₃ fluoroalkyl, C₁₋₃ cyanoalkyl, C₁₋₆         hydroxyalkyl, C₁₋₃ hydroxy-fluoroalkyl,         —CR_(x)R_(x)CR_(x)(OH)CR_(x)═CR_(x)R_(x),         —(CR_(x)R_(x))₁₋₄O(C₁₋₃ alkyl),         —(CR_(x)R_(x))₁₋₄O(CR_(x)R_(x))₁₋₃O(C₁₋₃ alkyl),         —CH₂CH(OH)CH₂O(C₁₋₃ alkyl), —(CR_(x)R_(x))₁₋₃S(C₁₋₃ alkyl),         —(CH₂)₁₋₃C(O)OC(CH₃)₃, —(CR_(x)R_(x))₀₋₃NR_(x)R_(y),         —(CR_(x)R_(x))₀₋₃NR_(x)(C₁₋₄ hydroxyalkyl),         —CH₂CH(OH)CH₂NR_(x)R_(y), —C(O)H, —C(O)(C₁₋₆ alkyl), —C(O)(C₁₋₃         hydroxyalkyl), —C(O)(C₁₋₃ fluoroalkyl), —C(O)(C₁₋₃ chloroalkyl),         —C(O)(C₁₋₃ cyanoalkyl), —(CR_(x)R_(x))₀₋₃C(O)OH,         —C(O)(CH₂)₀₋₂O(C₁₋₄ alkyl),         —C(O)(CR_(x)R_(x))₀₋₂O(CR_(x)R_(x))₁₋₂O(C₁₋₃ alkyl),         —C(O)CR_(x)R_(x)S(O)₂(C₁₋₃ alkyl),         —C(O)CR_(x)R_(x)NR_(x)S(O)₂(C₁₋₃ alkyl),         —C(O)CR_(x)R_(x)OC(O)(C₁₋₃ alkyl),         —C(O)(CR_(x)R_(x))₀₋₃NR_(y)R_(y),         —C(O)(CR_(x)R_(x))₀₋₁NR_(x)(C₁₋₃ cyanoalkyl),         —C(O)(CR_(x)R_(x))₀₋₂NR_(y)(C₁₋₆ hydroxyalkyl),         —C(O)(CR_(x)R_(x))₀₋₁NR_(x)(C₁₋₃ fluoroalkyl),         —C(O)(CR_(x)R_(x))₀₋₁NR_(x)(C₁₋₅ hydroxy-fluoroalkyl),         —C(O)(CR_(x)R_(x))₀₋₁NR_(x)(CH₂)₁₋₂O(C₁₋₃ hydroxyalkyl),         —C(O)(CR_(x)R_(x))₀₋₁NR_(x)(CH₂)₁₋₂NR_(x)C(O)(C₁₋₂ alkyl),         —C(O)(CR_(x)R_(x))₀₋₁NR_(x)((CR_(x)R_(x))₁₋₂O(C₁₋₂ alkyl)),         —C(O)CR_(x)(NH₂)(CR_(x)R_(x))₁₋₄NR_(x)R_(x),         —C(O)CR_(x)(NH₂)(CR_(x)R_(x))₁₋₄NR_(x)C(O)NR_(x)R_(x),         —C(O)(CR_(x)R_(x))₀₋₃NR_(x)(CH₂)₀₋₁C(O)(C₁₋₃ alkyl),         —C(O)(CR_(x)R_(x))₀₋₁NR_(x)(CH₂)₀₋₁C(O)(C₁₋₃ cyanoalkyl),         —C(O)(CR_(x)R_(x))₀₋₁NR_(x)(CH₂)₁₋₂C(O)NR_(y)R_(y),         —C(O)(CR_(x)R_(x))₁₋₃C(O)NR_(y)R_(y),         —C(O)(CR_(x)R_(x))₀₋₁NR_(x)(CHR_(y)(CH₂OH)),         —(CR_(x)R_(x))₁₋₂C(O)NR_(y)R_(y),         —(CR_(x)R_(x))₁₋₂C(O)NR_(y)(C₁₋₃ fluoroalkyl),         —(CR_(x)R_(x))₁₋₂C(O)NR_(y)(C₁₋₄ hydroxyalkyl),         —(CR_(x)R_(x))₁₋₂C(O)NR_(y)(C₁₋₃ cyanoalkyl),         —(CR_(x)R_(x))₁₋₂C(O)NR_(x)(CH₂)₁₋₂O(C₁₋₃ alkyl),         —(CR_(x)R_(x))₁₋₂C(O)NR_(x)CH(C₁₋₄ alkyl)(C₁₋₃ hydroxyalkyl),         —(CH₂)₁₋₂C(O)NR_(x)(CH₂)₁₋₂C(O)NR_(x)R_(x),         —(CH₂)₁₋₂C(O)NR_(x)(CH₂)₁₋₂S(O)₂OH,         —(CH₂)₁₋₂C(O)NR_(x)(CH₂)₁₋₂NR_(x)C(O)(C₁₋₃ alkyl),         —(CH₂)₁₋₂C(O)NR_(x)(CH₂)₁₋₃NR_(x)R_(x),         —(CH₂)₁₋₂C(O)N(CH₂CH₃)(CH₂)₁₋₃NR_(x)R_(x), —(CH₂)₀₋₂S(O)₂(C₁₋₄         alkyl), —(CH₂)₀₋₂S(O)₂(C₁₋₃ fluoroalkyl),         —(CH₂)₀₋₂S(O)₂NR_(x)R_(x), —C(O)C(O)OH, —C(O)C(O)NR_(y)R_(y), or         —C(O)C(O)NR_(y)(CR_(x)R_(x))₁₋₂NR_(y)R_(y); -   L₁ is a bond, —(CR_(x)R_(x))₁₋₂—, —(CR_(x)R_(x))₁₋₂CR_(x)(OH)—,     —(CR_(x)R_(x))₁₋₂O—, —CR_(x)R_(x)C(O)—,     —(CR_(x)R_(x))₂NR_(x)(CR_(x)R_(x))₀₋₁—,     —CR_(x)R_(x)C(O)NR_(x)(CR_(x)R_(x))₀₋₄—, —C(O)(CR_(x)R_(x))₀₋₃—,     —C(O)(CR_(x)R_(x))₀₋₂NR_(x)(CR_(x)R_(x))₀₋₂—,     —C(O)(CR_(x)R_(x))₀₋₂N(C₁₋₂ hydroxyalkyl)(CR_(x)R_(x))₀₋₂—,     —C(O)(CR_(x)R_(x))₀₋₂NR_(x)(CR_(x)R_(x))₁₋₂CR_(x)(OH)—,     —C(O)(CR_(x)R_(x))₁₋₂C(O)NR_(x)—,     —(CR_(x)R_(x))₀₋₂C(O)NR_(x)(CR_(x)R_(x))₁₋₂CR_(x)(OH)—,     —(CR_(x)R_(x))₀₋₂C(O)N(C₁₋₂ hydroxyalkyl)(CR_(x)R_(x))₁₋₂—,     —C(O)(CR_(x)R_(x))₀₋₁O—, —C(O)(CR_(x)R_(x))₁₋₂NHS(O)₂—,     —C(O)CR_(x)(NH₂)CR_(x)R_(x)—, —C(O)C(O)(CR_(x)R_(x))₀₋₂—,     —C(O)NR_(x)(CR_(x)R_(x))₁₋₂, or —S(O)₂—; -   A is 2-oxa-6-azaspiro[3,3]heptanyl, 4-oxaspiro[2.5]octanyl,     7-azaspiro[3.5]nonanyl, 8-azabicyclo[3.2.1]octanyl,     8-oxa-3-azabicyclo[3.2.1]octanyl, 9-azabicyclo[3.3.1]nonanyl,     adamantanyl, azepanyl, azetidinyl, C₃₋₆ cycloalkyl, diazepanyl,     dihydroinonyl, dihydropyrimidinonyl, dioxidoisothiazolidinyl,     dioxidothiazinanyl, dioxotetrahydrothiophenyl,     dioxotetrahydrothiopyranyl, dioxothiomorpholinyl, furanyl,     imidazolyl, imidazolidinonyl, indolyl, isoquinolinyl, isoxazolyl,     morpholinyl, morpholinonyl, naphthalenyl,     octahydrocyclopenta[b]pyranyl, oxazolidinonyl, oxadiazolyl,     oxetanyl, oxazolyl, phenyl, piperidinyl, piperidinonyl, piperazinyl,     piperazinonyl, pyrazinyl, pyrazolyl, pyridazinonyl, pyridinonyl,     pyridinyl, pyrimidinyl, pyrrolidinonyl, pyrrolidinyl, pyrrolyl,     quinolinyl, quinolizinonyl, tetrahydrofuranyl, tetrahydropyranyl,     tetrazolyl, thiadiazolyl, thiazolyl, or triazolyl, each substituted     with -L₂-R_(a) and zero to 4 R_(b); -   L₂ is a bond or —CR_(x)R_(x)—; -   R_(a) is:     -   (a) H, F, Cl, —CN, —OH, C₁₋₆ alkyl, C₁₋₃ fluoroalkyl, C₁₋₅         hydroxyalkyl, —(CH₂)₀₋₄O(C₁₋₃ alkyl), —(CR_(x)R_(x))₁₋₃S(C₁₋₃         alkyl), —(CR_(x)R_(x))₁₋₃NHC(O)O(C₁₋₄ alkyl),         —(CR_(x)R_(x))₁₋₃NR_(y)R_(y), —(CR_(x)R_(x))₁₋₃C(O)NR_(y)R_(y),         —O(C₁₋₃ fluoroalkyl), —S(O)₂NR_(x)R_(x),         —O(CR_(x)R_(x))₁₋₃NR_(x)R_(x), —NHS(O)₂(C₁₋₃ alkyl),         —NR_(x)R_(x), —NR_(x)(C₁₋₄ alkyl), —NR_(x)C(O)(C₁₋₄ alkyl),         —(CR_(x)R_(x))₀₋₃C(O)OH, —C(O)(C₁₋₅ alkyl), —C(O)(C₁₋₃         fluoroalkyl), —C(O)O(C₁₋₄ alkyl), —C(O)NH(C₁₋₃ cyanoalkyl),         —C(O)NR_(y)R_(y), —C(O)NR_(x)CH₂C(O)NR_(x)R_(x), or         —C(O)NR_(x)CH₂CH₂NHC(O)(C₁₋₃ alkyl);     -   (b) C₃₋₆ cycloalkyl or —C(O)NH(C₃₋₆ cycloalkyl), wherein each         cycloalkyl is substituted with zero to 2 substituents         independently selected from —OH, C₁₋₃ alkyl, C₁₋₃ hydroxyalkyl,         C₁₋₃ fluoroalkyl, and —C(O)O(C₁₋₃ alkyl); or     -   (c) A₁, —CH₂A₁, —C(O)A₁, —NR_(x)A₁, or —C(O)NR_(x)A₁, wherein A₁         is furanyl, imidazolyl, indolyl, isoxazolyl, morpholinyl,         octahydropyrrolo[3,4-c]pyrrolyl, oxazolyl, oxetanyl, phenyl,         piperazinyl, piperidinyl, pyrazolyl, pyridinyl, pyrimidinyl,         pyrrolidinyl, pyrrolyl, tetrahydrofuranyl, tetrahydropyranyl,         thiadiazolyl, thiazolyl, thiophenyl, or triazolyl, each         substituted with zero to three substituents independently         selected from —OH, C₁₋₃ alkyl, C₁₋₃ hydroxyalkyl, —C(O)(C₁₋₂         alkyl), —C(O)O(C₁₋₃ alkyl), —NR_(x)R_(x), phenyl,         trifluoromethyl-phenyl, —CH₂(bromophenyl), and         —CH₂CH₂(pyrrolidinyl); -   each R_(b) is independently F, —CH₃, —CF₃, or —OCH₃; -   each R_(x) is independently H or —CH₃; -   each R_(y) is independently H or C₁₋₆ alkyl; -   R_(z) is H, C₁₋₂ alkyl, or C₁₋₂ fluoroalkyl; -   R_(4a), R_(4b), R_(4c), and R_(4c) are independently H, F, —OH, C₁₋₂     alkyl, or —OCH₃; or R_(4a) and R_(4c) join together to form     —CH₂CH₂—; -   R₅ is F, Cl, —CN, C₁₋₂ alkyl, C₁₋₂ fluoroalkyl, or —OCH₃; -   m is zero, 1, 2, 3, or 4; -   n is zero, 1, or 2; and -   p is zero, 1, 2, 3, or 4.

One embodiment provides a compound of Formula (I) or a salt thereof, wherein R_(4a), R_(4b), R_(4c), and R_(4d) are independently H or —CH₃. Included in this embodiment are compounds in which R_(4a) and R_(4b) are each —CH₃; and R_(2c) and R_(2d) are each H. Also included in this embodiment are compounds in which R_(4a) is —CH₃; R_(4b) is H; R_(4c) is —CH₃; and R_(4d) is H.

One embodiment provides a compound of Formula (I) or a salt thereof, wherein R_(4a), R_(4b), R_(4c), and R_(4d) are each H.

One embodiment provides a compound of Formula (I) or a salt thereof, wherein R_(4a), R_(4b), R_(4c), and R_(4d) are each —CH₃.

One embodiment provides a compound of Formula (I) or a salt thereof, wherein: R_(4a) and R_(4c) join together to form —CH₂CH₂—; R_(4b) is H or —CH₃; and R_(4d) is H or —CH₃. Compounds of this embodiment have the structure of Formula (Ia):

-   Included in this embodiment are compounds in which R_(4b) and R_(4d)     are each H.

One embodiment provides a compound of Formula (I) or a salt thereof, wherein: R₁ is H, Cl, —CN, C₁₋₄ alkyl, or C₁₋₂ fluoroalkyl; each R₂ is independently F, Cl, —CN, —OH, C₁₋₃ alkyl, —OCH₃, —CH₂OH, —CH₂OCH₃, or —CH₂CH₂OCH₃; R₃ is (a) -L₁-A; or (b) H, C₁₋₄ alkyl, C₁₋₄ fluoroalkyl, C₁₋₄ hydroxyalkyl, C₁₋₃ cyanoalkyl, —(CR_(x)R_(x))₁₋₄O(C₁₋₃ alkyl), —(CH₂)₁₋₂S(O)₂(C₁₋₄ alkyl), —(CR_(x)R_(x))₁₋₂C(O)NR_(y)R_(y), or —C(O)(CR_(x)R_(x))₀₋₃NR_(y)R_(y); L₁ is a bond or —(CR_(x)R_(x))₁₋₂—; A is a ring selected from C₃₋₆ cycloalkyl, oxetanyl, tetrahydrofuranyl, tetrahydropyranyl, pyrazolyl, triazolyl, pyrimidinyl, oxazolidinonyl, pyrrolidinonyl, or dioxo-isothiazolidinyl, each substituted with R_(a) and zero to 4 R_(b); R_(a) is H, —CN, —OH, C₁₋₃ alkyl, C₁₋₂ fluoroalkyl, C₁₋₃ hydroxyalkyl, or —(CH₂)₁₋₂O(C₁₋₃ alkyl); each R_(b) is independently F, —CH₃, or —OCH₃; R_(4a), R_(4b), R_(4c), and R_(4d) are independently H or —CH₃; or R_(4a) and R_(4c) join together to form —CH₂CH₂—; n is zero or 1; and p is zero, 1, or 2.

One embodiment provides a compound of Formula (I) or a salt thereof, wherein: R₁ is —CH(CH₃)₂; each R₂ is independently Cl, —CH₃; —OCH₃, or —CH₂OCH₃; R₃ is H, —CH₃, —CH(CH₃)₂, —CH₂CN, —CH₂CH₂OH, —CH₂CH₂OCH₃, —CH₂CH₂S(O)₂CH₃, —CH₂CH₂CH₂CF₃, —CH₂C(CH₃)₂OH, —CH₂C(O)NH(CH₃), —CH₂C(O)N(CH₃)₂, —C(O)CH₂N(CH₃)₂, difluorocyclohexyl, oxetanyl, tetrahydrofuranyl, tetrahydropyranyl, —CH₂(oxetanyl), —CH₂(methyloxetanyl), —CH₂(methylpyrazolyl), —CH₂(methyltriazolyl), —CH₂(methylpyrimidinyl), —CH₂(methoxypyrimidinyl), —CH₂CH₂(oxazolidinonyl), —CH₂CH₂(pyrrolidinonyl), or —CH₂CH₂(dioxo-isothiazolidinyl); R_(4a), R_(4b), R_(4c), and R_(4d) are independently H or —CH₃; or R_(4a) and R_(4c) join together to form —CH₂CH₂—; n is zero; and p is zero, 1, or 2.

One embodiment provides a compound of Formula (I) or a salt thereof, wherein R₁ is H, Cl, —CN, C₁₋₄ alkyl, C₁₋₃ fluoroalkyl, C₁₋₃ hydroxy-fluoroalkyl, C₃₋₆ cycloalkyl, or —CH₂(C₃₋₆ cycloalkyl); and R₂, R₃, R_(4a), R_(4b), R_(4c), R_(4d), R₅, n, and p are defined in the first aspect. Included in this embodiment are compounds in which R₁ is H, Cl, —CN, C₁₋₄ alkyl, or C₁₋₂ fluoroalkyl. Also included in this embodiment are compounds in which R₁ is —CH(CH₃)₂.

One embodiment provides a compound of Formula (I) or a salt thereof, wherein each R₂ is independently F, Cl, —CN, —OH, C₁₋₃ alkyl, —OCH₃, —CH₂OH, —CH₂OCH₃, or —CH₂CH₂OCH₃; and R₁, R₃, R_(4a), R_(4b), R_(4c), R_(4d), R₅, n, and p are defined in the first aspect. Included in this embodiment are compounds in which each R₂ is independently Cl, —CH₃, —OCH₃, or —CH₂OCH₃. Also included in this embodiment are compounds in which each R₂ is independently Cl or —CH₃. Additionally, included in this embodiment are compounds in which R₁ is —CH(CH₃)₂.

One embodiment provides a compound of Formula (I) or a salt thereof, wherein each R₂ is independently Cl, —CH₃, —OCH₃, or —CH₂OCH₃; p is zero, 1, or 2; and R₁, R₃, R_(4a), R_(4b), R_(4c), R_(4d), R₅, and n are defined in the first aspect. Included in this embodiment are compounds in which p is 1; and R₂ is —CH₃. Also included in this embodiment are compounds in which p is 2; one R₂ is —CH₃ and the second R₂ is —CH₃ or Cl. Additionally, included in this embodiment are compounds in which R₁ is —CH(CH₃)₂.

One embodiment provides a compound of Formula (I) or a salt thereof, wherein p is zero; and R₁, R₃, R_(4a), R_(4b), R_(4c), R_(4d), R₅, and n are defined in the first aspect. Included in this embodiment are compounds in which R₁ is —CH(CH₃)₂.

One embodiment provides a compound of Formula (I) or a salt thereof, wherein R₃ is H; and R₁, R₂, R_(4a), R_(4b), R_(4c), R_(4d), R₅, n, and p are defined in the first aspect. Included in this embodiment are compounds in which R₁ is —CH(CH₃)₂.

One embodiment provides a compound of Formula (I) or a salt thereof, wherein R₃ is H, C₁₋₆ alkyl, C₁₋₃ fluoroalkyl, C₁₋₃ cyanoalkyl, C₁₋₆ hydroxyalkyl, C₁₋₃ hydroxy-fluoroalkyl, —CR_(x)R_(x)CR_(x)(OH)CR_(x)═CR_(x)R_(x), —(CR_(x)R_(x))₁₋₄O(C₁₋₃ alkyl), —(CR_(x)R_(x))₁₋₄O(CR_(x)R_(x))₁₋₃O(C₁₋₃ alkyl), —CH₂CH(OH)CH₂O(C₁₋₃ alkyl), —(CR_(x)R_(x))₁₋₃S(C₁₋₃ alkyl), —(CH₂)₁₋₃C(O)OC(CH₃)₃, —(CR_(x)R_(x))₀₋₃NR_(x)R_(y), —(CR_(x)R_(x))₀₋₃NR_(x)(C₁₋₄hydroxyalkyl), —CH₂CH(OH)CH₂NR_(x)R_(y), —C(O)H, —C(O)(C₁₋₆ alkyl), —C(O)(C₁₋₃ hydroxyalkyl), —C(O)(C₁₋₃ fluoroalkyl), —C(O)(C₁₋₃ chloroalkyl), —C(O)(C₁₋₃ cyanoalkyl), —(CR_(x)R_(x))₀₋₃C(O)OH, —C(O)(CH₂)₀₋₂O(C₁₋₄ alkyl), —C(O)(CR_(x)R_(x))₀₋₂O(CR_(x)R_(x))₁₋₂O(C₁₋₃ alkyl), —C(O)CR_(x)R_(x)S(O)₂(C₁₋₃ alkyl), —C(O)CR_(x)R_(x)NR_(x)S(O)₂(C₁₋₃ alkyl), —C(O)CR_(x)R_(x)OC(O)(C₁₋₃ alkyl), —C(O)(CR_(x)R_(x))₀₋₃NR_(y)R_(y), —C(O)(CR_(x)R_(x))₀₋₁NR_(x)(C₁₋₃ cyanoalkyl), —C(O)(CR_(x)R_(x))₀₋₂NR_(y)(C₁₋₆ hydroxyalkyl), —C(O)(CR_(x)R_(x))₀₋₁NR_(x)(C₁₋₃ fluoroalkyl), —C(O)(CR_(x)R_(x))₀₋₁NR_(x)(C₁₋₅ hydroxy-fluoroalkyl), —C(O)(CR_(x)R_(x))₀₋₁NR_(x)(CH₂)₁₋₂O(C₁₋₃ hydroxyalkyl), —C(O)(CR_(x)R_(x))₀₋₁NR_(x)(CH₂)₁₋₂NR_(x)C(O)(C₁₋₂ alkyl), —C(O)(CR_(x)R_(x))₀₋₁NR_(x)((CR_(x)R_(x))₁₋₂O(C₁₋₂ alkyl)), —C(O)CR_(x)(NH₂)(CR_(x)R_(x))₁₋₄NR_(x)R_(x), —C(O)CR_(x)(NH₂)(CR_(x)R_(x))₁₋₄NR_(x)C(O)NR_(x)R_(x), —C(O)(CR_(x)R_(x))₀₋₃NR_(x)(CH₂)₀₋₁C(O)(C₁₋₃ alkyl), —C(O)(CR_(x)R_(x))₀₋₁NR_(x)(CH₂)₀₋₁C(O)(C₁₋₃ cyanoalkyl), —C(O)(CR_(x)R_(x))₀₋₁NR_(x)(CH₂)₁₋₂C(O)NR_(y)R_(y), —C(O)(CR_(x)R_(x))₁₋₃C(O)NR_(y)R_(y), —C(O)(CR_(x)R_(x))₀₋₁NR_(x)(CHR_(y)(CH₂OH)), —(CR_(x)R_(x))₁₋₂C(O)NR_(y)R_(y), —(CR_(x)R_(x))₁₋₂C(O)NR_(y)(C₁₋₃ fluoroalkyl), —(CR_(x)R_(x))₁₋₂C(O)NR_(y)(C₁₋₄ hydroxyalkyl), —(CR_(x)R_(x))₁₋₂C(O)NR_(y)(C₁₋₃ cyanoalkyl), —(CR_(x)R_(x))₁₋₂C(O)NR_(x)(CH₂)₁₋₂O(C₁₋₃ alkyl), —(CR_(x)R_(x))₁₋₂C(O)NR_(x)CH(C₁₋₄ alkyl)(C₁₋₃ hydroxyalkyl), —(CH₂)₁₋₂C(O)NR_(x)(CH₂)₁₋₂C(O)NR_(x)R_(x), —(CH₂)₁₋₂C(O)NR_(x)(CH₂)₁₋₂S(O)₂OH, —(CH₂)₁₋₂C(O)NR_(x)(CH₂)₁₋₂NR_(x)C(O)(C₁₋₃ alkyl), —(CH₂)₁₋₂C(O)NR_(x)(CH₂)₁₋₃NR_(x)R_(x), —(CH₂)₁₋₂C(O)N(CH₂CH₃)(CH₂)₁₋₃NR_(x)R_(x), —(CH₂)₀₋₂S(O)₂(C₁₋₄ alkyl), —(CH₂)₀₋₂S(O)₂(C₁₋₃ fluoroalkyl), —(CH₂)₀₋₂S(O)₂NR_(x)R_(x), —C(O)C(O)OH, —C(O)C(O)NR_(y)R_(y), or —C(O)C(O)NR_(y)(CR_(x)R_(x))₁₋₂NR_(y)R_(y); and R₁, R₂, R_(4a), R_(4b), R_(4c), R_(4d), R₅, n, and p are defined in the first aspect.

One embodiment provides a compound of Formula (I) or a salt thereof, wherein R₃ is H, C₁₋₄ alkyl, C₁₋₄ fluoroalkyl, C₁₋₄ hydroxyalkyl, C₁₋₃ cyanoalkyl, —(CR_(x)R_(x))₁₋₄O(C₁₋₃ alkyl), —(CH₂)₁₋₂S(O)₂(C₁₋₄ alkyl), —(CR_(x)R_(x))₁₋₂C(O)NR_(y)R_(y), or —C(O)(CR_(x)R_(x))₀₋₃NR_(y)R_(y); and R₁, R₂, R_(4a), R_(4b), R_(4c), R_(4d), R₅, R_(x), R_(y), n, and p are defined in the first aspect. Included in this embodiment are compounds in which R₃ is H, C₁₋₃ alkyl, C₂₋₄ fluoroalkyl, C₁₋₄ hydroxyalkyl, C₁₋₂ cyanoalkyl, —(CR_(x)R_(x))₁₋₃OCH₃, —(CH₂)₁₋₂S(O)₂CH₃, —(CR_(x)R_(x))₁₋₂C(O)NR_(y)R_(y), or —C(O)(CH₂)₁₋₃NR_(y)R_(y). Also included in this embodiment are compounds in which R₃ is H, —CH₃, —CH(CH₃)₂, —CH₂CN, —CH₂CH₂OH, —CH₂CH₂OCH₃, —CH₂CH₂S(O)₂CH₃, —CH₂CH₂CH₂CF₃, —CH₂C(CH₃)₂OH, —CH₂C(O)NH(CH₃), —CH₂C(O)N(CH₃)₂, or —C(O)CH₂N(CH₃)₂. Additionally, included in this embodiment are compounds in which R₁ is —CH(CH₃)₂.

One embodiment provides a compound of Formula (I) or a salt thereof, wherein R₃ is -L₁-A; and R₁, R₂, R_(4a), R_(4b), R_(4c), R_(4d), R₅, A, L₁, n, and p are defined in the first aspect. Included in this embodiment are compounds in which L₁ is a bond or —(CR_(x)R_(x))₁₋₂—; A is a ring selected from C₃₋₆ cycloalkyl, oxetanyl, tetrahydrofuranyl, tetrahydropyranyl, pyrazolyl, triazolyl, pyrimidinyl, oxazolidinonyl, pyrrolidinonyl, or dioxo-isothiazolidinyl, each substituted with R_(a) and zero to 4 R_(b). Also included in this embodiment are compounds in which R₃ is cyclohexyl, oxetanyl, tetrahydrofuranyl, tetrahydropyranyl, pyrazolyl, triazolyl, pyrimidinyl, pyrimidinyl, oxazolidinonyl, pyrrolidinonyl, or dioxo-isothiazolidinyl; R_(a) is H, —CN, —OH, C₁₋₃ alkyl, C₁₋₂ fluoroalkyl, C₁₋₃ hydroxyalkyl, or —(CH₂)₁₋₂O(C₁₋₃ alkyl); and each R_(b) is independently F, —CH₃, or —OCH₃.

One embodiment provides a compound of Formula (I) or a salt thereof, wherein said compound is selected from 6-(3-isopropyl-5-(piperidin-4-yl)-1H-indol-2-yl)-[1,2,4] triazolo[4,3-a]pyridine (1); 6-(3-isopropyl-5-(piperidin-4-yl)-1H-indol-2-yl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridine (2); 6-(3-isopropyl-5-(piperidin-4-yl)-1H-indol-2-yl)-3-methyl-[1,2,4]triazolo[4,3-a]pyridine (3); 6-(3-isopropyl-5-(piperidin-4-yl)-1H-indol-2-yl)-7-methyl-[1,2,4]triazolo[4,3-a]pyridine (4); 6-(3-isopropyl-5-(piperidin-4-yl)-1H-indol-2-yl)-5-methyl-[1,2,4]triazolo[4,3-a]pyridine (5); 6-(3-isopropyl-5-(piperidin-4-yl)-1H-indol-2-yl)-3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (6); 6-(3-isopropyl-5-(piperidin-4-yl)-1H-indol-2-yl)-3-(methoxymethyl)-[1,2,4]triazolo[4,3-a]pyridine (7); 6-(3-isopropyl-5-(piperidin-4-yl)-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a] pyridine (8); 6-(3-isopropyl-5-(piperidin-4-yl)-1H-indol-2-yl)-5,8-dimethyl-[1,2,4] triazolo[4,3-a]pyridine (9); 8-chloro-6-(3-isopropyl-5-(piperidin-4-yl)-1H-indol-2-yl)-7-methyl-[1,2,4]triazolo[4,3-a]pyridine (10); 6-(3-isopropyl-5-(piperidin-4-yl)-1H-indol-2-yl)-8-methoxy-[1,2,4]triazolo[4,3-a]pyridine (11); 2-(4-(3-isopropyl-2-(8-methyl-[1,2,4] triazolo[4,3-a]pyridin-6-yl)-1H-indol-5-yl)piperidin-1-yl)-N,N-dimethylacetamide (12); 2-(4-(2-([1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-isopropyl-1H-indol-5-yl)piperidin-1-yl)-N-methylacetamide (13); 2-(4-(2-([1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-isopropyl-1H-indol-5-yl)piperidin-1-yl)-N,N-dimethylacetamide (14); 2-(4-(3-isopropyl-2-(7-methyl-[1,2,4] triazolo[4,3-a]pyridin-6-yl)-1H-indol-5-yl)piperidin-1-yl)-N-methylacetamide (15); 2-(4-(3-isopropyl-2-(8-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1H-indol-5-yl)piperidin-1-yl)-N-methylacetamide (16); 2-(4-(3-isopropyl-2-(3-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1H-indol-5-yl)piperidin-1-yl)-N-methylacetamide (17); 2-(4-(3-isopropyl-2-(7-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1H-indol-5-yl)piperidin-1-yl)-N,N-dimethylacetamide (18); 2-(4-(3-isopropyl-2-(3-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1H-indol-5-yl)piperidin-1-yl)-N,N-dimethylacetamide (19); 6-(3-isopropyl-5-(1-((1-methyl-1H-1,2,4-triazol-3-yl)methyl)piperidin-4-yl)-1H-indol-2-yl)-7-methyl-[1,2,4] triazolo[4,3-a]pyridine (20); 6-(3-isopropyl-5-(1-((1-methyl-1H-1,2,4-triazol-3-yl) methyl)piperidin-4-yl)-1H-indol-2-yl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridine (21); 6-(3-isopropyl-5-(1-((1-methyl-1H-1,2,4-triazol-3-yl)methyl)piperidin-4-yl)-1H-indol-2-yl)-3-methyl-[1,2,4]triazolo[4,3-a]pyridine (22); 6-(3-isopropyl-5-(1-((1-methyl-1H-1,2,4-triazol-3-yl)methyl)piperidin-4-yl)-1H-indol-2-yl)-[1,2,4]triazolo[4,3-a]pyridine (23); 2-(4-(3-isopropyl-2-(5-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1H-indol-5-yl)piperidin-1-yl)-N-methylacetamide (24); 2-(4-(3-isopropyl-2-(5-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1H-indol-5-yl)piperidin-1-yl)-N,N-dimethylacetamide (25); 6-(3-isopropyl-5-(1-((1-methyl-1H-1,2,4-triazol-3-yl)methyl)piperidin-4-yl)-1H-indol-2-yl)-5-methyl-[1,2,4]triazolo[4,3-a]pyridine (26); 6-(3-isopropyl-5-(1-(2-methoxyethyl) piperidin-4-yl)-1H-indol-2-yl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridine (27); 2-(4-(3-isopropyl-2-(8-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1H-indol-5-yl)piperidin-1-yl) ethan-1-ol (28); 6-(3-isopropyl-5-(1-((3-methyloxetan-3-yl)methyl)piperidin-4-yl)-1H-indol-2-yl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridine (29); 6-(3-isopropyl-5-(1-(oxetan-3-ylmethyl)piperidin-4-yl)-1H-indol-2-yl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridine (30); 2-(4-(2-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-isopropyl-1H-indol-5-yl) piperidin-1-yl)acetonitrile (31); 6-(3-isopropyl-5-(1-(2-(methylsulfonyl)ethyl)piperidin-4-yl)-1H-indol-2-yl)-3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (32); 6-(3-isopropyl-5-(1-((1-methyl-1H-1,2,4-triazol-3-yl)methyl)piperidin-4-yl)-1H-indol-2-yl)-3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (33); 2-(4-(2-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-isopropyl-1H-indol-5-yl)piperidin-1-yl)-N,N-dimethylacetamide (34); 6-(3-isopropyl-5-(1-(2-(methylsulfonyl)ethyl)piperidin-4-yl)-1H-indol-2-yl)-8-methyl-[1,2,4] triazolo[4,3-a]pyridine (35); 6-(3-isopropyl-5-(1-(4,4,4-trifluorobutyl)piperidin-4-yl)-1H-indol-2-yl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridine (36); 2-(4-(3-isopropyl-2-(8-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1H-indol-5-yl)piperidin-1-yl)acetonitrile (37); 2-(4-(3-isopropyl-2-(3-(methoxymethyl)-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1H-indol-5-yl)piperidin-1-yl)-N,N-dimethylacetamide (38); 2-(4-(2-(7,8-dimethyl-[1,2,4]triazolo [4,3-a]pyridin-6-yl)-3-isopropyl-1H-indol-5-yl)piperidin-1-yl)-N,N-dimethylacetamide (39); 6-(3-isopropyl-5-(1-((1-methyl-1H-1,2,4-triazol-3-yl)methyl)piperidin-4-yl)-1H-indol-2-yl)-5,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (40); 6-(3-isopropyl-5-(1-(4,4,4-trifluorobutyl)piperidin-4-yl)-1H-indol-2-yl)-5,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (41); 2-(4-(2-(5,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-isopropyl-1H-indol-5-yl)piperidin-1-yl)-N,N-dimethylacetamide (42); 6-(3-isopropyl-5-(1-(2-(methylsulfonyl) ethyl)piperidin-4-yl)-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (43); 6-(3-isopropyl-5-(1-(4,4,4-trifluorobutyl)piperidin-4-yl)-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (44); 6-(3-isopropyl-5-(1-((1-methyl-1H-1,2,4-triazol-3-yl) methyl)piperidin-4-yl)-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (45); 8-chloro-6-(3-isopropyl-5-(1-(2-(methylsulfonyl)ethyl)piperidin-4-yl)-1H-indol-2-yl)-7-methyl-[1,2,4]triazolo[4,3-a]pyridine (46); 8-chloro-6-(3-isopropyl-5-(1-((1-methyl-1H-1,2,4-triazol-3-yl)methyl)piperidin-4-yl)-1H-indol-2-yl)-7-methyl-[1,2,4]triazolo[4,3-a] pyridine (47); 8-chloro-6-(3-isopropyl-5-(1-(4,4,4-trifluorobutyl)piperidin-4-yl)-1H-indol-2-yl)-7-methyl-[1,2,4]triazolo[4,3-a]pyridine (48); 2-(4-(2-(8-chloro-7-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-isopropyl-1H-indol-5-yl)piperidin-1-yl)-N,N-dimethylacetamide (49); 2-(4-(2-(8-chloro-7-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-isopropyl-1H-indol-5-yl)piperidin-1-yl)acetonitrile (50); 2-(4-(2-(7,8-dimethyl-[1,2,4] triazolo[4,3-a]pyridin-6-yl)-3-isopropyl-1H-indol-5-yl)piperidin-1-yl)acetonitrile (51); 2-(2-(4-(2-(7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-isopropyl-1H-indol-5-yl) piperidin-1-yl)ethyl)isothiazolidine 1,1-dioxide (52); 2-(2-(4-(2-(8-chloro-7-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-isopropyl-1H-indol-5-yl)piperidin-1-yl)ethyl) isothiazolidine 1,1-dioxide (53); 2-(4-(3-isopropyl-2-(8-methoxy-[1,2,4]triazolo[4,3-a] pyridin-6-yl)-1H-indol-5-yl)piperidin-1-yl)-N,N-dimethylacetamide (54); 6-(3-isopropyl-5-(1-(4,4,4-trifluorobutyl)piperidin-4-yl)-1H-indol-2-yl)-8-methoxy-[1,2,4]triazolo[4,3-a] pyridine (55); 3-(2-(4-(2-(7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-isopropyl-1H-indol-5-yl)piperidin-1-yl)ethyl)oxazolidin-2-one (56); 1-(2-(4-(2-(7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-isopropyl-1H-indol-5-yl)piperidin-1-yl)ethyl) pyrrolidin-2-one (57); 1-(4-(3-isopropyl-2-(8-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1H-indol-5-yl)piperidin-1-yl)-2-methylpropan-2-ol (58); 1-(4-(2-(5,8-dimethyl-[1,2,4] triazolo[4,3-a]pyridin-6-yl)-3-isopropyl-1H-indol-5-yl)piperidin-1-yl)-2-methylpropan-2-ol (59); 1-(4-(2-(7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-isopropyl-1H-indol-5-yl)piperidin-1-yl)-2-methylpropan-2-ol (60); 1-(4-(2-(8-chloro-7-methyl-[1,2,4]triazolo [4,3-a]pyridin-6-yl)-3-isopropyl-1H-indol-5-yl)piperidin-1-yl)-2-methylpropan-2-ol (61); 1-(4-(3-isopropyl-2-(8-methoxy-5-methyl-[1,2,4]triazolo[4,3-a)pyridin-6-yl)-1H-indol-5-yl)piperidin-1-yl)-2-methylpropan-2-ol (62); 6-(3-isopropyl-5-(1-(oxetan-3-yl)piperidin-4-yl)-1H-indol-2-yl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridine (63); 6-(3-isopropyl-5-(1-(tetrahydro-2H-pyran-4-yl)piperidin-4-yl)-1H-indol-2-yl)-[1,2,4]triazolo[4,3-a]pyridine (64); 6-(3-isopropyl-5-(1-(oxetan-3-yl)piperidin-4-yl)-1H-indol-2-yl)-[1,2,4]triazolo[4,3-a]pyridine (65); 6-(3-isopropyl-5-(1-(oxetan-3-yl)piperidin-4-yl)-1H-indol-2-yl)-7-methyl-[1,2,4]triazolo[4,3-a]pyridine (66); 6-(3-isopropyl-5-(1-(oxetan-3-yl)piperidin-4-yl)-1H-indol-2-yl)-3-methyl-[1,2,4]triazolo[4,3-a]pyridine (67); 6-(3-isopropyl-5-(1-(tetrahydro-2H-pyran-4-yl)piperidin-4-yl)-1H-indol-2-yl)-7-methyl-[1,2,4]triazolo[4,3-a] pyridine (68); 6-(3-isopropyl-5-(1-(tetrahydro-2H-pyran-4-yl)piperidin-4-yl)-1H-indol-2-yl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridine (69); 6-(3-isopropyl-5-(1-(tetrahydro-2H-pyran-4-yl)piperidin-4-yl)-1H-indol-2-yl)-5-methyl-[1,2,4]triazolo[4,3-a]pyridine (70); 6-(3-isopropyl-5-(1-((1-methyl-1H-pyrazol-3-yl)methyl)piperidin-4-yl)-1H-indol-2-yl)-3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (71); 6-(3-isopropyl-5-(1-(oxetan-3-yl)piperidin-4-yl)-1H-indol-2-yl)-3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (72); 6-(3-isopropyl-5-(1-(tetrahydro-2H-pyran-4-yl)piperidin-4-yl)-1H-indol-2-yl)-3,8-dimethyl-[1,2,4]triazolo [4,3-a]pyridine (73); 6-(3-isopropyl-5-(1-((1-methyl-1H-pyrazol-3-yl)methyl)piperidin-4-yl)-1H-indol-2-yl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridine (74); 6-(3-isopropyl-5-(1-(oxetan-3-yl)piperidin-4-yl)-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (75); 6-(3-isopropyl-5-(1-(oxetan-3-yl)piperidin-4-yl)-1H-indol-2-yl)-5,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (76); 6-(3-isopropyl-5-(1-(tetrahydro-2H-pyran-4-yl) piperidin-4-yl)-1H-indol-2-yl)-5,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (77); 6-(3-isopropyl-5-(1-(tetrahydro-2H-pyran-4-yl)piperidin-4-yl)-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (78); 6-(3-isopropyl-5-(1-((3-methyloxetan-3-yl)methyl) piperidin-4-yl)-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (79); 8-chloro-6-(3-isopropyl-5-(1-((3-methyloxetan-3-yl)methyl)piperidin-4-yl)-1H-indol-2-yl)-7-methyl-[1,2,4]triazolo[4,3-a)pyridine (80); 8-chloro-6-(3-isopropyl-5-(1-(tetrahydro-2H-pyran-4-yl)piperidin-4-yl)-1H-indol-2-yl)-7-methyl-[1,2,4]triazolo[4,3-a]pyridine (81); 8-chloro-6-(3-isopropyl-5-(1-(oxetan-3-yl)piperidin-4-yl)-1H-indol-2-yl)-7-methyl-[1,2,4] triazolo[4,3-a]pyridine (82); 6-(3-isopropyl-5-(1-((1-methyl-1H-1,2,3-triazol-4-yl) methyl)piperidin-4-yl)-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (83); 8-chloro-6-(3-isopropyl-5-(1-((1-methyl-1H-1,2,3-triazol-4-yl)methyl)piperidin-4-yl)-1H-indol-2-yl)-7-methyl-[1,2,4]triazolo[4,3-a]pyridine (84); 6-(5-(1-(2,2-dimethyltetrahydro-2H-pyran-4-yl)piperidin-4-yl)-3-isopropyl-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (85); 6-(3-isopropyl-5-(1-(oxetan-3-yl)piperidin-4-yl)-1H-indol-2-yl)-8-methoxy-[1,2,4]triazolo[4,3-a]pyridine (86); 6-(5-(1-(2,6-dimethyltetrahydro-2H-pyran-4-yl)piperidin-4-yl)-3-isopropyl-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (87); 6-(3-isopropyl-5-(1-(tetrahydro-2H-pyran-4-yl)piperidin-4-yl)-1H-indol-2-yl)-8-methoxy-[1,2,4]triazolo[4,3-a]pyridine (88); 6-(3-isopropyl-5-(1-((2-methoxypyrimidin-5-yl)methyl)piperidin-4-yl)-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (89); 6-(3-isopropyl-5-(1-((3-methyloxetan-3-yl) methyl)piperidin-4-yl)-1H-indol-2-yl)-8-methoxy-[1,2,4]triazolo[4,3-a]pyridine (90); 6-(3-isopropyl-5-(1-((2-methylpyrimidin-5-yl)methyl)piperidin-4-yl)-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (91); 6-(5-(1-(2,6-dimethyltetrahydro-2H-pyran-4-yl)piperidin-4-yl)-3-isopropyl-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a] pyridine (92); 6-(3-isopropyl-5-(1-(tetrahydrofuran-3-yl)piperidin-4-yl)-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a)pyridine (93); 6-(3-isopropyl-5-(1-(tetrahydrofuran-3-yl)piperidin-4-yl)-1H-indol-2-yl)-8-methoxy-[1,2,4]triazolo[4,3-a]pyridine (94); 6-(5-(1-(4,4-difluorocyclohexyl)piperidin-4-yl)-3-isopropyl-1H-indol-2-yl)-8-methoxy-[1,2,4] triazolo[4,3-a]pyridine (95); 6-(3-isopropyl-5-(1-methylpiperidin-4-yl)-1H-indol-2-yl)-8-methoxy-[1,2,4]triazolo[4,3-a)pyridine (96); 6-(3-isopropyl-5-(1-isopropylpiperidin-4-yl)-1H-indol-2-yl)-8-methoxy-[1,2,4]triazolo[4,3-a]pyridine (97); 6-(3-isopropyl-5-(1-methylpiperidin-4-yl)-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (98); 6-(3-isopropyl-5-(1-isopropylpiperidin-4-yl)-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo [4,3-a]pyridine (99); 6-(3-isopropyl-5-(1-(2,2,6,6-tetramethyltetrahydro-2H-pyran-4-yl) piperidin-4-yl)-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (100); 6-(5-(1-(4,4-difluorocyclohexyl)piperidin-4-yl)-3-isopropyl-1H-indol-2-yl)-7,8-dimethyl-[1,2,4] triazolo[4,3-a]pyridine (101); 6-(3-isopropyl-5-(1-(tetrahydrofuran-3-yl)piperidin-4-yl)-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (102 and 103); 2-(dimethylamino)-1-(4-(3-isopropyl-2-(8-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1H-indol-5-yl)piperidin-1-yl)ethanone (104); 1-(4-(2-([1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-isopropyl-1H-indol-5-yl)piperidin-1-yl)-2-(dimethylamino)ethan-1-one (105); 2-(dimethylamino)-1-(4-(3-isopropyl-2-(3-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1H-indol-5-yl)piperidin-1-yl)ethan-1-one (106); 2-(dimethylamino)-1-(4-(3-isopropyl-2-(7-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1H-indol-5-yl)piperidin-1-yl)ethan-1-one (107); 2-(dimethylamino)-1-(4-(3-isopropyl-2-(5-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1H-indol-5-yl)piperidin-1-yl)ethan-1-one (108); 6-(5-(2,6-dimethylpiperidin-4-yl)-3-isopropyl-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (109); 6-(5-(2,6-dimethyl-1-(2-(methylsulfonyl)ethyl)piperidin-4-yl)-3-isopropyl-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (110 to 111); 2-(4-(2-(7,8-dimethyl-[1,2,4] triazolo[4,3-a]pyridin-6-yl)-3-isopropyl-1H-indol-5-yl)-2,6-dimethylpiperidin-1-yl)-N,N-dimethylacetamide (112); 6-(5-(2,6-dimethyl-1-((3-methyloxetan-3-yl)methyl)piperidin-4-yl)-3-isopropyl-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (113 to 114); and 6-(5-(2,6-dimethyl-1-(oxetan-3-yl)piperidin-4-yl)-3-isopropyl-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (115).

One embodiment provides a compound of Formula (Ia) or a salt thereof wherein R₁ is —CH(CH₃)₂; each R₂ is —CH₃; R₃ is H, —CH₂C(O)N(CH₃)₂, oxetanyl, or —CH₂(methyl oxetanyl); R_(4b) is H; R_(4d) is H; n is zero; and p is zero, 1, or 2. Included in this embodiment are compounds in which p is 2.

One embodiment provides a compound of Formula (I) or a salt thereof, wherein said compound is selected from 6-(5-(8-azabicyclo[3.2.1]octan-3-yl)-3-isopropyl-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (116 and 117); 2-((1R,5S)-3-(2-(7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-isopropyl-1H-indol-5-yl)-8-azabicyclo [3.2.1]octan-8-yl)-N,N-dimethylacetamide (118 and 119); 6-(3-isopropyl-5-((1R,5S)-8-((3-methyloxetan-3-yl)methyl)-8-azabicyclo[3.2.1]octan-3-yl)-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (120 and 121); and 6-(3-isopropyl-5-((1R,5S)-8-(oxetan-3-yl)-8-azabicyclo[3.2.1]octan-3-yl)-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo [4,3-a]pyridine (122 and 123).

The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The invention encompasses all combinations of the aspects and/or embodiments of the invention noted herein. It is understood that any and all embodiments of the present invention may be taken in conjunction with any other embodiment or embodiments to describe additional embodiments. It is also to be understood that each individual element of the embodiments is meant to be combined with any and all other elements from any embodiment to describe an additional embodiment.

Definitions

The features and advantages of the invention may be more readily understood by those of ordinary skill in the art upon reading the following detailed description. It is to be appreciated that certain features of the invention that are, for clarity reasons, described above and below in the context of separate embodiments, may also be combined to form a single embodiment. Conversely, various features of the invention that are, for brevity reasons, described in the context of a single embodiment, may also be combined so as to form sub-combinations thereof. Embodiments identified herein as exemplary or preferred are intended to be illustrative and not limiting.

Unless specifically stated otherwise herein, references made in the singular may also include the plural. For example, “a” and “an” may refer to either one, or one or more.

As used herein, the phrase “compounds” refers to at least one compound. For example, a compound of Formula (I) includes a compound of Formula (I) and two or more compounds of Formula (I).

Unless otherwise indicated, any heteroatom with unsatisfied valences is assumed to have hydrogen atoms sufficient to satisfy the valences.

The definitions set forth herein take precedence over definitions set forth in any patent, patent application, and/or patent application publication incorporated herein by reference.

Listed below are definitions of various terms used to describe the present invention. These definitions apply to the terms as they are used throughout the specification (unless they are otherwise limited in specific instances) either individually or as part of a larger group.

Throughout the specification, groups and substituents thereof may be chosen by one skilled in the field to provide stable moieties and compounds.

In accordance with a convention used in the art,

is used in structural formulas herein to depict the bond that is the point of attachment of the moiety or substituent to the core or backbone structure.

The terms “halo” and “halogen,” as used herein, refer to F, Cl, Br, and I.

The term “cyano” refers to the group —CN.

The term “amino” refers to the group —NH₂.

The term “oxo” refers to the group ═O.

The term “alkyl” as used herein, refers to both branched and straight-chain saturated aliphatic hydrocarbon groups containing, for example, from 1 to 12 carbon atoms, from 1 to 6 carbon atoms, and from 1 to 4 carbon atoms. Examples of alkyl groups include, but are not limited to, methyl (Me), ethyl (Et), propyl (e.g., n-propyl and i-propyl), butyl (e.g., n-butyl, i-butyl, sec-butyl, and t-butyl), and pentyl (e.g., n-pentyl, isopentyl, neopentyl), n-hexyl, 2-methylpentyl, 2-ethylbutyl, 3-methylpentyl, and 4-methylpentyl. When numbers appear in a subscript after the symbol “C”, the subscript defines with more specificity the number of carbon atoms that a particular group may contain. For example, “C₁₋₆ alkyl” denotes straight and branched chain alkyl groups with one to six carbon atoms.

The term “fluoroalkyl” as used herein is intended to include both branched and straight-chain saturated aliphatic hydrocarbon groups substituted with one or more fluorine atoms. For example, “C₁₋₄ fluoroalkyl” is intended to include C₁, C₂, C₃, and C₄ alkyl groups substituted with one or more fluorine atoms. Representative examples of fluoroalkyl groups include, but are not limited to, —CF₃ and —CH₂CF₃.

The term “chloroalkyl” as used herein is intended to include both branched and straight-chain saturated aliphatic hydrocarbon groups substituted with one or more chlorine atoms. For example, “C₁₋₄ chloroalkyl” is intended to include C₁, C₂, C₃, and C₄ alkyl groups substituted with one or more chlorine atoms. Representative examples of fluoroalkyl groups include, but are not limited to, —CCl₃ and —CH₂CCl₃.

The term “cyanoalkyl” includes both branched and straight-chain saturated alkyl groups substituted with one or more cyano groups. For example, “cyanoalkyl” includes —CH₂CN, —CH₂CH₂CN, and C₁₋₄ cyanoalkyl.

The term “aminoalkyl” includes both branched and straight-chain saturated alkyl groups substituted with one or more amino groups. For example, “aminoalkyl” includes —CH₂NH₂, —CH₂CH₂NH₂, and C₁₋₄ aminoalkyl.

The term “hydroxyalkyl” includes both branched and straight-chain saturated alkyl groups substituted with one or more hydroxyl groups. For example, “hydroxyalkyl” includes —CH₂OH, —CH₂CH₂OH, and C₁₋₄ hydroxyalkyl.

The term “hydroxy-fluoroalkyl” includes both branched and straight-chain saturated alkyl groups substituted with one or more hydroxyl groups and one or more fluorine atoms. For example, “hydroxy-fluoroalkyl” includes —CHFCH₂OH, —CH₂CHFC(CH₃)₂OH, and C₁₋₄ hydroxy-fluoroalkyl.

The term “cycloalkyl,” as used herein, refers to a group derived from a non-aromatic monocyclic or polycyclic hydrocarbon molecule by removal of one hydrogen atom from a saturated ring carbon atom. Representative examples of cycloalkyl groups include, but are not limited to, cyclopropyl, cyclopentyl, and cyclohexyl. When numbers appear in a subscript after the symbol “C”, the subscript defines with more specificity the number of carbon atoms that a particular cycloalkyl group may contain. For example, “C₃-C₆ cycloalkyl” denotes cycloalkyl groups with three to six carbon atoms.

The term “alkoxy,” as used herein, refers to an alkyl group attached to the parent molecular moiety through an oxygen atom, for example, methoxy group (—OCH₃). For example, “C₁₋₃ alkoxy” denotes alkoxy groups with one to three carbon atoms.

The terms “fluoroalkoxy” and “—O(fluoroalkyl)” represent a fluoroalkyl group as defined above attached through an oxygen linkage (—O—). For example, “C₁₋₄ fluoroalkoxy” is intended to include C₁, C₂, C₃, and C₄ fluoroalkoxy groups.

The term “alkoxyalkoxy,” as used herein, refers to an alkoxy group attached to the parent molecular moiety through an alkoxy group, for example, methoxymethoxy group (—OCH₂OCH₃). For example, “C₁₋₄ alkoxyalkoxy” denotes alkoxy groups with one to four carbon atoms.

The term “benzyl,” as used herein, refers to a methyl group in which one of the hydrogen atoms is replaced by a phenyl group. The phenyl ring may be unsubstituted or may contain one or more substituents as valence allows.

The phrase “pharmaceutically acceptable” is employed herein to refer to those compounds, materials, compositions, and/or dosage forms which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of human beings and animals without excessive toxicity, irritation, allergic response, or other problem or complication, commensurate with a reasonable benefit/risk ratio.

The compounds of Formula (I) can be provided as amorphous solids or crystalline solids. Lyophilization can be employed to provide the compounds of Formula (I) as amorphous solids.

It should further be understood that solvates (e.g., hydrates) of the compounds of Formula (I) are also within the scope of the present invention. The term “solvate” means a physical association of a compound of Formula (I) with one or more solvent molecules, whether organic or inorganic. This physical association includes hydrogen bonding. In certain instances the solvate will be capable of isolation, for example when one or more solvent molecules are incorporated in the crystal lattice of the crystalline solid. “Solvate” encompasses both solution-phase and isolable solvates. Exemplary solvates include hydrates, ethanolates, methanolates, isopropanolates, acetonitrile solvates, and ethyl acetate solvates. Methods of solvation are known in the art.

Various forms of prodrugs are well known in the art and are described in:

a) The Practice of Medicinal Chemistry, Camille G. Wermuth et al., Ch 31, (Academic Press, 1996);

b) Design of Prodrugs, edited by H. Bundgaard, (Elsevier, 1985);

c) A Textbook of Drug Design and Development, P. Krogsgaard-Larson and H. Bundgaard, eds. Ch 5, pgs 113-191 (Harwood Academic Publishers, 1991); and

d) Hydrolysis in Drug and Prodrug Metabolism, Bernard Testa and Joachim M. Mayer, (Wiley-VCH, 2003).

In addition, compounds of Formula (I), subsequent to their preparation, can be isolated and purified to obtain a composition containing an amount by weight equal to or greater than 99% of a compound of Formula (I) (“substantially pure”), which is then used or formulated as described herein. Such “substantially pure” compounds of Formula (I) are also contemplated herein as part of the present invention.

“Stable compound” and “stable structure” are meant to indicate a compound that is sufficiently robust to survive isolation to a useful degree of purity from a reaction mixture, and formulation into an efficacious therapeutic agent. The present invention is intended to embody stable compounds.

“Therapeutically effective amount” is intended to include an amount of a compound of the present invention alone or an amount of the combination of compounds claimed or an amount of a compound of the present invention in combination with other active ingredients effective to act as an inhibitor to TLR7/8/9, or effective to treat or prevent autoimmune and/or inflammatory disease states, such as SLE, IBD, multiple sclerosis (MS), Sjögren's syndrome, and rheumatoid arthritis.

As used herein, “treating” or “treatment” cover the treatment of a disease-state in a mammal, particularly in a human, and include: (a) preventing the disease-state from occurring in a mammal, in particular, when such mammal is predisposed to the disease-state but has not yet been diagnosed as having it; (b) inhibiting the disease-state, i.e., arresting its development; and/or (c) relieving the disease-state, i.e., causing regression of the disease state.

The compounds of the present invention are intended to include all isotopes of atoms occurring in the present compounds. Isotopes include those atoms having the same atomic number but different mass numbers. By way of general example and without limitation, isotopes of hydrogen include deuterium (D) and tritium (T). Isotopes of carbon include ¹³C and ¹⁴C. Isotopically-labeled compounds of the invention can generally be prepared by conventional techniques known to those skilled in the art or by processes analogous to those described herein, using an appropriate isotopically-labeled reagent in place of the non-labeled reagent otherwise employed. For example, methyl (—CH₃) also includes deuterated methyl groups such as —CD₃.

Utility

The human immune system has evolved to defend the body from micro-organisms, viruses, and parasites that can cause infection, disease or death. Complex regulatory mechanisms ensure that the various cellular components of the immune system target the foreign substances or organisms, while not causing permanent or significant damage to the individual. While the initiating events are not well understood at this time, in autoimmune disease states the immune system directs its inflammatory response to target organs in the afflicted individual. Different autoimmune diseases are typically characterized by the predominate or initial target organ or tissues affected; such as the joint in the case of rheumatoid arthritis, the thyroid gland in the case of Hashimoto's thyroiditis, the central nervous system in the case of multiple sclerosis, the pancreas in the case of type I diabetes, and the bowel in the case of inflammatory bowel disease.

The compounds of the invention inhibit signaling through Toll-like receptor 7, or 8, or 9 (TLR7, TLR8, TLR9) or combinations thereof. Accordingly, compounds of Formula (I) have utility in treating conditions associated with the inhibition of signaling through one or more of TLR7, TLR8, or TLR9. Such conditions include TLR7, TLR8, or TLR9 receptor associated diseases in which cytokine levels are modulated as a consequence of intracellular signaling.

As used herein, the terms “treating” or “treatment” encompass the treatment of a disease state in a mammal, particularly in a human, and include: (a) preventing or delaying the occurrence of the disease state in a mammal, in particular, when such mammal is predisposed to the disease state but has not yet been diagnosed as having it; (b) inhibiting the disease state, i.e., arresting its development; and/or (c) achieving a full or partial reduction of the symptoms or disease state, and/or alleviating, ameliorating, lessening, or curing the disease or disorder and/or its symptoms.

In view of their activity as selective inhibitors of TLR7, TLR8, or TLR9, the compounds of Formula (I) are useful in treating TLR7, TLR8, or TLR9 family receptor associated diseases, but not limited to, inflammatory diseases such as Crohn's disease, ulcerative colitis, asthma, graft versus host disease, allograft rejection, chronic obstructive pulmonary disease; autoimmune diseases such as Graves' disease, rheumatoid arthritis, systemic lupus erythematosus, psoriasis; auto-inflammatory diseases including CAPS, TRAPS, FMF, adult onset Still's disease, systemic onset juvenile idiopathic arthritis, gout, gouty arthritis; metabolic diseases including type 2 diabetes, atherosclerosis, myocardial infarction; destructive bone disorders such as bone resorption disease, osteoarthritis, osteoporosis, multiple myeloma-related bone disorder; proliferative disorders such as acute myelogenous leukemia, chronic myelogenous leukemia; angiogenic disorders such as angiogenic disorders including solid tumors, ocular neovasculization, and infantile haemangiomas; infectious diseases such as sepsis, septic shock, and Shigellosis; neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, cerebral ischemias or neurodegenerative disease caused by traumatic injury, oncologic and viral diseases such as metastatic melanoma, Kaposi's sarcoma, multiple myeloma, and HIV infection and CMV retinitis, AIDS, respectively.

More particularly, the specific conditions or diseases that may be treated with the inventive compounds include, without limitation, pancreatitis (acute or chronic), asthma, allergies, adult respiratory distress syndrome, chronic obstructive pulmonary disease, glomerulonephritis, rheumatoid arthritis, systemic lupus erythematosus, scleroderma, chronic thyroiditis, Graves' disease, autoimmune gastritis, diabetes, autoimmune hemolytic anemia, autoimmune neutropenia, thrombocytopenia, atopic dermatitis, chronic active hepatitis, myasthenia gravis, multiple sclerosis, inflammatory bowel disease, ulcerative colitis, Crohn's disease, psoriasis, graft vs. host disease, inflammatory reaction induced by endotoxin, tuberculosis, atherosclerosis, muscle degeneration, cachexia, psoriatic arthritis, Reiter's syndrome, gout, traumatic arthritis, rubella arthritis, acute synovitis, pancreatic β-cell disease; diseases characterized by massive neutrophil infiltration; rheumatoid spondylitis, gouty arthritis and other arthritic conditions, cerebral malaria, chronic pulmonary inflammatory disease, silicosis, pulmonary sarcoidosis, bone resorption disease, allograft rejections, fever and myalgias due to infection, cachexia secondary to infection, keloid formation, scar tissue formation, ulcerative colitis, pyresis, influenza, osteoporosis, osteoarthritis, acute myelogenous leukemia, chronic myelogenous leukemia, metastatic melanoma, Kaposi's sarcoma, multiple myeloma, sepsis, septic shock, and Shigellosis; Alzheimer's disease, Parkinson's disease, cerebral ischemias or neurodegenerative disease caused by traumatic injury; angiogenic disorders including solid tumors, ocular neovasculization, and infantile haemangiomas; viral diseases including acute hepatitis infection (including hepatitis A, hepatitis B and hepatitis C), HIV infection and CMV retinitis, AIDS, ARC or malignancy, and herpes; stroke, myocardial ischemia, ischemia in stroke heart attacks, organ hypoxia, vascular hyperplasia, cardiac and renal reperfusion injury, thrombosis, cardiac hypertrophy, thrombin-induced platelet aggregation, endotoxemia and/or toxic shock syndrome, conditions associated with prostaglandin endoperoxidase syndase-2, and pemphigus vulgaris. Preferred methods of treatment are those wherein the condition is selected from Crohn's disease, ulcerative colitis, allograft rejection, rheumatoid arthritis, psoriasis, ankylosing spondylitis, psoriatic arthritis, and pemphigus vulgaris. Alternatively preferred methods of treatment are those wherein the condition is selected from ischemia reperfusion injury, including cerebral ischemia reperfusions injury arising from stroke and cardiac ischemia reperfusion injury arising from myocardial infarction. Another preferred method of treatment is one in which the condition is multiple myeloma.

In one embodiment, the compounds of Formula (I) are useful in treating cancer, including Waldenstrom's Macroglobulinemia (WM), diffuse large B cell lymphoma (DLBCL), chronic lymphocytic leukemia (CLL), cutaneous diffuse large B cell lymphoma, and primary CNS lymphoma.

In addition, the TLR7, TLR8, or TLR9 inhibitors of the present invention inhibit the expression of inducible pro-inflammatory proteins such as prostaglandin endoperoxide synthase-2 (PGHS-2), also referred to as cyclooxygenase-2 (COX-2), IL-1, IL-6, IL-18, chemokines. Accordingly, additional TLR7/8/9 associated conditions include edema, analgesia, fever and pain, such as neuromuscular pain, headache, pain caused by cancer, dental pain and arthritis pain. The inventive compounds also may be used to treat veterinary viral infections, such as lentivirus infections, including, but not limited to equine infectious anemia virus; or retrovirus infections, including feline immunodeficiency virus, bovine immunodeficiency virus, and canine immunodeficiency virus.

The present invention thus provides methods for treating such conditions, comprising administering to a subject in need thereof a therapeutically-effective amount of at least one compound of Formula (I) or a salt thereof. “Therapeutically effective amount” is intended to include an amount of a compound of the present invention that is effective when administered alone or in combination to inhibit autoimmune disease or chronic inflammatory disease.

The methods of treating TLR7, TLR8, or TLR9 associated conditions may comprise administering compounds of Formula (I) alone or in combination with each other and/or other suitable therapeutic agents useful in treating such conditions. Accordingly, “therapeutically effective amount” is also intended to include an amount of the combination of compounds claimed that is effective to inhibit TLR7, TLR8, or TLR9 and/or treat diseases associated with TLR7, TLR8, or TLR9.

Exemplary of such other therapeutic agents include corticosteroids, rolipram, calphostin, cytokine-suppressive anti-inflammatory drugs (CSAIDs), Interleukin-10, glucocorticoids, salicylates, nitric oxide, and other immunosuppressants; nuclear translocation inhibitors, such as deoxyspergualin (DSG); non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen, celecoxib and rofecoxib; steroids such as prednisone or dexamethasone; antiviral agents such as abacavir; antiproliferative agents such as methotrexate, leflunomide, FK506 (tacrolimus, PROGRAF®); anti-malarials such as hydroxychloroquine; cytotoxic drugs such as azathiprine and cyclophosphamide; TNF-α inhibitors such as tenidap, anti-TNF antibodies or soluble TNF receptor, and rapamycin (sirolimus or RAPAMUNE®) or derivatives thereof.

The above other therapeutic agents, when employed in combination with the compounds of the present invention, may be used, for example, in those amounts indicated in the Physicians' Desk Reference (PDR) or as otherwise determined by one of ordinary skill in the art. In the methods of the present invention, such other therapeutic agent(s) may be administered prior to, simultaneously with, or following the administration of the inventive compounds. The present invention also provides pharmaceutical compositions capable of treating TLR7/8/9 receptor-associated conditions, including IL-1 family receptor-mediated diseases as described above.

The inventive compositions may contain other therapeutic agents as described above and may be formulated, for example, by employing conventional solid or liquid vehicles or diluents, as well as pharmaceutical additives of a type appropriate to the mode of desired administration (e.g., excipients, binders, preservatives, stabilizers, flavors, etc.) according to techniques such as those well known in the art of pharmaceutical formulation.

Accordingly, the present invention further includes compositions comprising one or more compounds of Formula (I) and a pharmaceutically acceptable carrier.

A “pharmaceutically acceptable carrier” refers to media generally accepted in the art for the delivery of biologically active agents to animals, in particular, mammals. Pharmaceutically acceptable carriers are formulated according to a number of factors well within the purview of those of ordinary skill in the art. These include without limitation the type and nature of the active agent being formulated; the subject to which the agent-containing composition is to be administered; the intended route of administration of the composition; and, the therapeutic indication being targeted. Pharmaceutically acceptable carriers include both aqueous and non-aqueous liquid media, as well as a variety of solid and semi-solid dosage forms. Such carriers can include a number of different ingredients and additives in addition to the active agent, such additional ingredients being included in the formulation for a variety of reasons, e.g., stabilization of the active agent, binders, etc., well known to those of ordinary skill in the art. Descriptions of suitable pharmaceutically acceptable carriers, and factors involved in their selection, are found in a variety of readily available sources such as, for example, Remington's Pharmaceutical Sciences, 17th Edition (1985), which is incorporated herein by reference in its entirety.

Compounds in accordance with Formula (I) can be administered by any means suitable for the condition to be treated, which can depend on the need for site-specific treatment or quantity of Formula (I) compound to be delivered.

Also embraced within this invention is a class of pharmaceutical compositions comprising a compound of Formula (I) and one or more non-toxic, pharmaceutically-acceptable carriers and/or diluents and/or adjuvants (collectively referred to herein as “carrier” materials) and, if desired, other active ingredients. The compounds of Formula (I) may be administered by any suitable route, preferably in the form of a pharmaceutical composition adapted to such a route, and in a dose effective for the treatment intended. The compounds and compositions of the present invention may, for example, be administered orally, mucosally, or parenterally including intravascularly, intravenously, intraperitoneally, subcutaneously, intramuscularly, and intrasternally in dosage unit formulations containing conventional pharmaceutically acceptable carriers, adjuvants, and vehicles. For example, the pharmaceutical carrier may contain a mixture of mannitol or lactose and microcrystalline cellulose. The mixture may contain additional components such as a lubricating agent, e.g. magnesium stearate and a disintegrating agent such as crospovidone. The carrier mixture may be filled into a gelatin capsule or compressed as a tablet. The pharmaceutical composition may be administered as an oral dosage form or an infusion, for example.

For oral administration, the pharmaceutical composition may be in the form of, for example, a tablet, capsule, liquid capsule, suspension, or liquid. The pharmaceutical composition is preferably made in the form of a dosage unit containing a particular amount of the active ingredient. For example, the pharmaceutical composition may be provided as a tablet or capsule comprising an amount of active ingredient in the range of from about 0.1 to 1000 mg, preferably from about 0.25 to 250 mg, and more preferably from about 0.5 to 100 mg. A suitable daily dose for a human or other mammal may vary widely depending on the condition of the patient and other factors, but, can be determined using routine methods.

Any pharmaceutical composition contemplated herein can, for example, be delivered orally via any acceptable and suitable oral preparations. Exemplary oral preparations, include, but are not limited to, for example, tablets, troches, lozenges, aqueous and oily suspensions, dispersible powders or granules, emulsions, hard and soft capsules, liquid capsules, syrups, and elixirs. Pharmaceutical compositions intended for oral administration can be prepared according to any methods known in the art for manufacturing pharmaceutical compositions intended for oral administration. In order to provide pharmaceutically palatable preparations, a pharmaceutical composition in accordance with the invention can contain at least one agent selected from sweetening agents, flavoring agents, coloring agents, demulcents, antioxidants, and preserving agents.

A tablet can, for example, be prepared by admixing at least one compound of Formula (I) with at least one non-toxic pharmaceutically acceptable excipient suitable for the manufacture of tablets. Exemplary excipients include, but are not limited to, for example, inert diluents, such as, for example, calcium carbonate, sodium carbonate, lactose, calcium phosphate, and sodium phosphate; granulating and disintegrating agents, such as, for example, microcrystalline cellulose, sodium crosscarmellose, corn starch, and alginic acid; binding agents, such as, for example, starch, gelatin, polyvinyl-pyrrolidone, and acacia; and lubricating agents, such as, for example, magnesium stearate, stearic acid, and talc. Additionally, a tablet can either be uncoated, or coated by known techniques to either mask the bad taste of an unpleasant tasting drug, or delay disintegration and absorption of the active ingredient in the gastrointestinal tract thereby sustaining the effects of the active ingredient for a longer period. Exemplary water soluble taste masking materials, include, but are not limited to, hydroxypropyl-methylcellulose and hydroxypropyl-cellulose. Exemplary time delay materials, include, but are not limited to, ethyl cellulose and cellulose acetate butyrate.

Hard gelatin capsules can, for example, be prepared by mixing at least one compound of Formula (I) with at least one inert solid diluent, such as, for example, calcium carbonate; calcium phosphate; and kaolin.

Soft gelatin capsules can, for example, be prepared by mixing at least one compound of Formula (I) with at least one water soluble carrier, such as, for example, polyethylene glycol; and at least one oil medium, such as, for example, peanut oil, liquid paraffin, and olive oil.

An aqueous suspension can be prepared, for example, by admixing at least one compound of Formula (I) with at least one excipient suitable for the manufacture of an aqueous suspension. Exemplary excipients suitable for the manufacture of an aqueous suspension, include, but are not limited to, for example, suspending agents, such as, for example, sodium carboxymethylcellulose, methylcellulose, hydroxypropylmethyl-cellulose, sodium alginate, alginic acid, polyvinyl-pyrrolidone, gum tragacanth, and gum acacia; dispersing or wetting agents, such as, for example, a naturally-occurring phosphatide, e.g., lecithin; condensation products of alkylene oxide with fatty acids, such as, for example, polyoxyethylene stearate; condensation products of ethylene oxide with long chain aliphatic alcohols, such as, for example heptadecaethylene-oxycetanol; condensation products of ethylene oxide with partial esters derived from fatty acids and hexitol, such as, for example, polyoxyethylene sorbitol monooleate; and condensation products of ethylene oxide with partial esters derived from fatty acids and hexitol anhydrides, such as, for example, polyethylene sorbitan monooleate. An aqueous suspension can also contain at least one preservative, such as, for example, ethyl and n-propyl p-hydroxybenzoate; at least one coloring agent; at least one flavoring agent; and/or at least one sweetening agent, including but not limited to, for example, sucrose, saccharin, and aspartame.

Oily suspensions can, for example, be prepared by suspending at least one compound of Formula (I) in either a vegetable oil, such as, for example, arachis oil; olive oil; sesame oil; and coconut oil; or in mineral oil, such as, for example, liquid paraffin. An oily suspension can also contain at least one thickening agent, such as, for example, beeswax; hard paraffin; and cetyl alcohol. In order to provide a palatable oily suspension, at least one of the sweetening agents already described hereinabove, and/or at least one flavoring agent can be added to the oily suspension. An oily suspension can further contain at least one preservative, including, but not limited to, for example, an anti-oxidant, such as, for example, butylated hydroxyanisol, and alpha-tocopherol.

Dispersible powders and granules can, for example, be prepared by admixing at least one compound of Formula (I) with at least one dispersing and/or wetting agent; at least one suspending agent; and/or at least one preservative. Suitable dispersing agents, wetting agents, and suspending agents are as already described above. Exemplary preservatives include, but are not limited to, for example, anti-oxidants, e.g., ascorbic acid. In addition, dispersible powders and granules can also contain at least one excipient, including, but not limited to, for example, sweetening agents; flavoring agents; and coloring agents.

An emulsion of at least one compound of Formula (I) thereof can, for example, be prepared as an oil-in-water emulsion. The oily phase of the emulsions comprising compounds of Formula (I) may be constituted from known ingredients in a known manner. The oil phase can be provided by, but is not limited to, for example, a vegetable oil, such as, for example, olive oil and arachis oil; a mineral oil, such as, for example, liquid paraffin; and mixtures thereof. While the phase may comprise merely an emulsifier, it may comprise a mixture of at least one emulsifier with a fat or an oil or with both a fat and an oil. Suitable emulsifying agents include, but are not limited to, for example, naturally-occurring phosphatides, e.g., soy bean lecithin; esters or partial esters derived from fatty acids and hexitol anhydrides, such as, for example, sorbitan monooleate; and condensation products of partial esters with ethylene oxide, such as, for example, polyoxyethylene sorbitan monooleate. Preferably, a hydrophilic emulsifier is included together with a lipophilic emulsifier which acts as a stabilizer. It is also preferred to include both an oil and a fat. Together, the emulsifier(s) with or without stabilizer(s) make-up the so-called emulsifying wax, and the wax together with the oil and fat make up the so-called emulsifying ointment base which forms the oily dispersed phase of the cream formulations. An emulsion can also contain a sweetening agent, a flavoring agent, a preservative, and/or an antioxidant. Emulsifiers and emulsion stabilizers suitable for use in the formulation of the present invention include Tween 60, Span 80, cetostearyl alcohol, myristyl alcohol, glyceryl monostearate, sodium lauryl sulfate, glyceryl distearate alone or with a wax, or other materials well known in the art.

The compounds of Formula (I) can, for example, also be delivered intravenously, subcutaneously, and/or intramuscularly via any pharmaceutically acceptable and suitable injectable form. Exemplary injectable forms include, but are not limited to, for example, sterile aqueous solutions comprising acceptable vehicles and solvents, such as, for example, water, Ringer's solution, and isotonic sodium chloride solution; sterile oil-in-water microemulsions; and aqueous or oleaginous suspensions.

Formulations for parenteral administration may be in the form of aqueous or non-aqueous isotonic sterile injection solutions or suspensions. These solutions and suspensions may be prepared from sterile powders or granules using one or more of the carriers or diluents mentioned for use in the formulations for oral administration or by using other suitable dispersing or wetting agents and suspending agents. The compounds may be dissolved in water, polyethylene glycol, propylene glycol, ethanol, corn oil, cottonseed oil, peanut oil, sesame oil, benzyl alcohol, sodium chloride, tragacanth gum, and/or various buffers. Other adjuvants and modes of administration are well and widely known in the pharmaceutical art. The active ingredient may also be administered by injection as a composition with suitable carriers including saline, dextrose, or water, or with cyclodextrin (i.e. Captisol), cosolvent solubilization (i.e. propylene glycol) or micellar solubilization (i.e. Tween 80).

The sterile injectable preparation may also be a sterile injectable solution or suspension in a non-toxic parenterally acceptable diluent or solvent, for example as a solution in 1,3-butanediol. Among the acceptable vehicles and solvents that may be employed are water, Ringer's solution, and isotonic sodium chloride solution. In addition, sterile, fixed oils are conventionally employed as a solvent or suspending medium. For this purpose any bland fixed oil may be employed, including synthetic mono- or diglycerides. In addition, fatty acids such as oleic acid find use in the preparation of injectables.

A sterile injectable oil-in-water microemulsion can, for example, be prepared by 1) dissolving at least one compound of Formula (I) in an oily phase, such as, for example, a mixture of soybean oil and lecithin; 2) combining the Formula (I) containing oil phase with a water and glycerol mixture; and 3) processing the combination to form a microemulsion.

A sterile aqueous or oleaginous suspension can be prepared in accordance with methods already known in the art. For example, a sterile aqueous solution or suspension can be prepared with a non-toxic parenterally-acceptable diluent or solvent, such as, for example, 1,3-butane diol; and a sterile oleaginous suspension can be prepared with a sterile non-toxic acceptable solvent or suspending medium, such as, for example, sterile fixed oils, e.g., synthetic mono- or diglycerides; and fatty acids, such as, for example, oleic acid.

Pharmaceutically acceptable carriers, adjuvants, and vehicles that may be used in the pharmaceutical compositions of this invention include, but are not limited to, ion exchangers, alumina, aluminum stearate, lecithin, self-emulsifying drug delivery systems (SEDDS) such as d-alpha-tocopherol polyethyleneglycol 1000 succinate, surfactants used in pharmaceutical dosage forms such as Tweens, polyethoxylated castor oil such as CREMOPHOR surfactant (BASF), or other similar polymeric delivery matrices, serum proteins, such as human serum albumin, buffer substances such as phosphates, glycine, sorbic acid, potassium sorbate, partial glyceride mixtures of saturated vegetable fatty acids, water, salts or electrolytes, such as protamine sulfate, disodium hydrogen phosphate, potassium hydrogen phosphate, sodium chloride, zinc salts, colloidal silica, magnesium trisilicate, polyvinyl pyrrolidone, cellulose-based substances, polyethylene glycol, sodium carboxymethylcellulose, polyacrylates, waxes, polyethylene-polyoxypropylene-block polymers, polyethylene glycol and wool fat. Cyclodextrins such as alpha-, beta-, and gamma-cyclodextrin, or chemically modified derivatives such as hydroxyalkylcyclodextrins, including 2- and 3-hydroxypropyl-cyclodextrins, or other solubilized derivatives may also be advantageously used to enhance delivery of compounds of the formulae described herein.

The pharmaceutically active compounds of this invention can be processed in accordance with conventional methods of pharmacy to produce medicinal agents for administration to patients, including humans and other mammals. The pharmaceutical compositions may be subjected to conventional pharmaceutical operations such as sterilization and/or may contain conventional adjuvants, such as preservatives, stabilizers, wetting agents, emulsifiers, buffers etc. Tablets and pills can additionally be prepared with enteric coatings. Such compositions may also comprise adjuvants, such as wetting, sweetening, flavoring, and perfuming agents.

The amounts of compounds that are administered and the dosage regimen for treating a disease condition with the compounds and/or compositions of this invention depends on a variety of factors, including the age, weight, sex, the medical condition of the subject, the type of disease, the severity of the disease, the route and frequency of administration, and the particular compound employed. Thus, the dosage regimen may vary widely, but can be determined routinely using standard methods. A daily dose of about 0.001 to 100 mg/kg body weight, preferably between about 0.0025 and about 50 mg/kg body weight and most preferably between about 0.005 to 10 mg/kg body weight, may be appropriate. The daily dose can be administered in one to four doses per day. Other dosing schedules include one dose per week and one dose per two day cycle.

For therapeutic purposes, the active compounds of this invention are ordinarily combined with one or more adjuvants appropriate to the indicated route of administration. If administered orally, the compounds may be admixed with lactose, sucrose, starch powder, cellulose esters of alkanoic acids, cellulose alkyl esters, talc, stearic acid, magnesium stearate, magnesium oxide, sodium and calcium salts of phosphoric and sulfuric acids, gelatin, acacia gum, sodium alginate, polyvinylpyrrolidone, and/or polyvinyl alcohol, and then tableted or encapsulated for convenient administration. Such capsules or tablets may contain a controlled-release formulation as may be provided in a dispersion of active compound in hydroxypropylmethyl cellulose.

Pharmaceutical compositions of this invention comprise at least one compound of Formula (I) and optionally an additional agent selected from any pharmaceutically acceptable carrier, adjuvant, and vehicle. Alternate compositions of this invention comprise a compound of the Formula (I) described herein, or a prodrug thereof, and a pharmaceutically acceptable carrier, adjuvant, or vehicle.

The present invention also encompasses an article of manufacture. As used herein, article of manufacture is intended to include, but not be limited to, kits and packages. The article of manufacture of the present invention, comprises: (a) a first container; (b) a pharmaceutical composition located within the first container, wherein the composition, comprises: a first therapeutic agent, comprising: a compound of the present invention or a pharmaceutically acceptable salt form thereof; and, (c) a package insert stating that the pharmaceutical composition can be used for the treatment of a cardiovascular and/or inflammatory disorder (as defined previously). In another embodiment, the package insert states that the pharmaceutical composition can be used in combination (as defined previously) with a second therapeutic agent to treat cardiovascular and/or inflammatory disorder. The article of manufacture can further comprise: (d) a second container, wherein components (a) and (b) are located within the second container and component (c) is located within or outside of the second container. Located within the first and second containers means that the respective container holds the item within its boundaries.

The first container is a receptacle used to hold a pharmaceutical composition. This container can be for manufacturing, storing, shipping, and/or individual/bulk selling. First container is intended to cover a bottle, jar, vial, flask, syringe, tube (e.g., for a cream preparation), or any other container used to manufacture, hold, store, or distribute a pharmaceutical product.

The second container is one used to hold the first container and, optionally, the package insert. Examples of the second container include, but are not limited to, boxes (e.g., cardboard or plastic), crates, cartons, bags (e.g., paper or plastic bags), pouches, and sacks. The package insert can be physically attached to the outside of the first container via tape, glue, staple, or another method of attachment, or it can rest inside the second container without any physical means of attachment to the first container. Alternatively, the package insert is located on the outside of the second container. When located on the outside of the second container, it is preferable that the package insert is physically attached via tape, glue, staple, or another method of attachment. Alternatively, it can be adjacent to or touching the outside of the second container without being physically attached.

The package insert is a label, tag, marker, etc. that recites information relating to the pharmaceutical composition located within the first container. The information recited will usually be determined by the regulatory agency governing the area in which the article of manufacture is to be sold (e.g., the United States Food and Drug Administration). Preferably, the package insert specifically recites the indications for which the pharmaceutical composition has been approved. The package insert may be made of any material on which a person can read information contained therein or thereon. Preferably, the package insert is a printable material (e.g., paper, plastic, cardboard, foil, adhesive-backed paper or plastic, etc.) on which the desired information has been formed (e.g., printed or applied).

Methods of Preparation

The compounds of the present invention can be prepared in a number of ways well known to one skilled in the art of organic synthesis. The compounds of the present invention can be synthesized using the methods described below, together with synthetic methods known in the art of synthetic organic chemistry, or variations thereon as appreciated by those skilled in the art. Preferred methods include, but are not limited to, those described below. All references cited herein are hereby incorporated in their entirety by reference.

The compounds of this invention may be prepared using the reactions and techniques described in this section. The reactions are performed in solvents appropriate to the reagents and materials employed and are suitable for the transformations being effected. Also, in the description of the synthetic methods described below, it is to be understood that all proposed reaction conditions, including choice of solvent, reaction atmosphere, reaction temperature, duration of the experiment and work up procedures, are chosen to be the conditions standard for that reaction, which should be readily recognized by one skilled in the art. It is understood by one skilled in the art of organic synthesis that the functionality present on various portions of the molecule must be compatible with the reagents and reactions proposed. Such restrictions to the substituents that are compatible with the reaction conditions will be readily apparent to one skilled in the art and alternate methods must then be used. This will sometimes require a judgment to modify the order of the synthetic steps or to select one particular process scheme over another in order to obtain a desired compound of the invention. It will also be recognized that another major consideration in the planning of any synthetic route in this field is the judicious choice of the protecting group used for protection of the reactive functional groups present in the compounds described in this invention. An authoritative account describing the many alternatives to the trained practitioner is Greene and Wuts (Protective Groups In Organic Synthesis, Third Edition, Wiley and Sons, 1999).

Compounds of Formula (I) may be prepared by reference to the methods illustrated in the following Scheme. As shown therein the end product is a compound having the same structural formula as Formula (I). It will be understood that any compound of Formula (I) may be produced by the schemes by the suitable selection of reagents with appropriate substitution. Solvents, temperatures, pressures, and other reaction conditions may readily be selected by one of ordinary skill in the art. Starting materials are commercially available or readily prepared by one of ordinary skill in the art. Constituents of compounds are as defined herein or elsewhere in the specification.

As shown in Scheme 1, compounds of Formula I may be produced, starting with the substituted 5-bromoindoles (2). 2 can be prepared from the 3-H indoles, via alkylation. Transition metal catalyzed cross coupling of 2 and boronate 3 followed by olefin reduction, bromination, and transition metal catalyzed borylation affords 4, which can then be coupled with bromo-substituted [1,2,4]triazolo[4,3-a]pyridines and deprotected to give 6. Alkylation of 6 leads to the production of the compounds of Formula I.

Abbreviations

-   Ac acetyl -   ACN acetonitrile -   anhyd. anhydrous -   aq. aqueous -   Bn benzyl -   Bu butyl -   Boc tert-butoxycarbonyl -   DBU 1,8-diazabicyclo[5.4.0]undec-7-ene -   DCE dichloroethane -   DCM dichloromethane -   DMF dimethylformamide -   DMSO dimethylsulfoxide -   EtOAc ethyl acetate -   Et ethyl -   EtOH ethanol -   Et₃N triethylamine -   H or H₂ hydrogen -   h, hr or hrs hour(s) -   i iso -   HCl hydrochloric acid -   HPLC high pressure liquid chromatography -   LC liquid chromatography -   M molar -   mM millimolar -   Me methyl -   MeOH methanol -   MHz megahertz -   min. minute(s) -   mins minute(s) -   MS mass spectrometry -   n or N normal -   NBS n-bromosuccinimide -   nm nanometer -   nM nanomolar -   PdCl₂(dppf)     [1,1′-bis(diphenylphosphino)ferrocene]dichloropalladium(II) -   Ph phenyl -   Pr propyl -   PSI pounds per square inch -   Ret Time retention time -   sat. saturated -   T3P propane phosphonic anhydride -   TEA triethylamine -   TFA trifluoroacetic acid -   THF tetrahydrofuran -   XPhos G2 Precatalyst     chloro(2-dicyclohexylphosphino-2′,4′,6′-triisopropyl-1,1′-biphenyl)[2-(2′-amino-1,1′-biphenyl)]palladium(II)     Analytical HPLC Conditions: -   QC-ACN-AA-XB: Column: Waters XBridge C18, 2.1 mm×50 mm, 1.7 μm     particles; Mobile Phase A: 5:95 acetonitrile:water with 10 mM     ammonium acetate; Mobile Phase B: 95:5 acetonitrile:water with 10 mM     ammonium acetate; Temperature: 50° C.; Gradient: 0% B to 100% B over     3 min, then a 0.75 min hold at 100% B; Flow: 1 mL/min; Detection: MS     and UV (220 nm). -   QC-ACN-TFA-XB: Column: Waters XBridge C18, 2.1 mm×50 mm, 1.7 μm     particles; Mobile Phase A: 5:95 acetonitrile:water with 0.1%     trifluoroacetic acid; Mobile Phase B: 95:5 acetonitrile:water with     0.1% trifluoroacetic acid; Temperature: 50° C.; Gradient: 0% B to     100% B over 3 min, then a 0.75 min hold at 100% B; Flow: 1 mL/min;     Detection: MS and UV (220 nm). -   (TS1): Column: Waters Acquity UPLC BEH C18 (2.1×50 mm), 1.7 micron;     Solvent A=100% water with 0.05% TFA; Solvent B=100% acetonitrile     with 0.05% TFA; gradient=2-98% B over 1 minute, then a 0.5-minute     hold at 98% B; Flow rate: 0.8 mL/min; Detection: UV at 254 nm. -   (B): Waters Acquity BEH C18 (2.1×50 mm) 1.7 micron; Buffer: 5 mM     ammonium acetate pH 5 adjusted with HCOOH, Solvent A: Buffer:ACN     (95:5), Solvent B: Buffer:ACN (5:95), Method: % B: 0 min-5%: 1.1     min-95%: 1.7 min-95%, Flow: 0.8 mL/min. -   (C): Column-Ascentis Express C18 (50×2.1 mm-2.7 μm) Mobile phase A:     0.1% HCOOH in water; Mobile phase B: ACN. Temperature: 50° C.;     Gradient: 0-100% B over 3 minutes; Flow rate: 1.0 mL/min. -   (D): Kinetex XB-C18 (75×3 mm) 2.6 micron; Solvent A: 10 mM ammonium     formate in water: acetonitrile (98:02); Mobile Phase B: 10 mM     ammonium formate in water:acetonitrile (02:98); Temperature: 50° C.;     Gradient: 0-100% B over 3 minutes; Flow rate: 1.1 mL/min; Detection:     UV at 220 nm. -   (H): Column: Acentis Express C18 (50×2.1 mm) 1.7 μm, Acentis C8     NH₄COOH 5 min. M, Mobile Phase A: −10 mM ammonium formate: ACN     (98:2), Mobile Phase B: −10 mM ammonium formate:ACN (2:98), Flow: 1     mL/min.

Template 1: tert-butyl 4-(2-bromo-3-isopropyl-1H-indol-5-yl)piperidine-1-carboxylate

Intermediate T-1A: 5-bromo-3-isopropyl-1H-indole

A 250 mL round bottom flask was charged with triethylsilane (8.90 g, 77 mmol), trichloroacetic acid (6.25 g, 38.3 mmol) and toluene (50 mL). The solution was heated to 70° C., then a solution of 5-bromo-1H-indole (5.0 g, 25.5 mmol) and acetone (2.247 mL, 30.6 mmol) in toluene (30 mL) was added drop wise via an addition funnel. The resulting brown solution was heated at 70° C. for 1.5 h. The solution was cooled to 10° C., quenched with 10% sodium bicarbonate and diluted with diethyl ether. The organic layer was separated, dried, and concentrated under vacuum to afford crude compound. The crude material was purified using silica gel chromatography eluting with 5% ethyl acetate in hexanes to afford 5-bromo-3-isopropyl-1H-indole (5.5 g, 23.10 mmol 95% yield) as an oil. LC retention time 1.42 min [D]. MS (E−) m/z: 238.2 (M+H).

Intermediate T-1B: tert-butyl 4-(3-isopropyl-1H-indol-5-yl)-5,6-dihydropyridine-1(2H)-carboxylate

To a mixture of 5-bromo-3-isopropyl-1H-indole (5.5 g, 23.10 mmol), tert-butyl 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-5,6-dihydropyridine-1(2H)-carboxylate (7.50 g, 24.25 mmol) in a 250 mL round bottom flask were added THF (50 mL) followed by aqueous solution of potassium phosphate, dibasic (12.07 g, 69.3 mmol, 20 mL). The resulting reaction mixture was degassed for 10 minutes with nitrogen gas, then PdCl₂(dppf)-CH₂Cl₂ adduct, (0.472 g, 0.577 mmol) was added. The mixture was degassed again for 5 min. The resulting reaction mixture was heated at 75° C. for 18 hours. The reaction mixture was diluted with ethyl acetate (100 mL), poured into a separate funnel and was washed with water (2×50 mL), brine (50 mL), dried over sodium sulfate, and concentrated to afford crude product. The crude material was purified using silica gel chromatography, eluting with 15% ethyl acetate in hexane. The fractions were collected and concentrated to afford tert-butyl 4-(3-isopropyl-1H-indol-5-yl)-5,6-dihydropyridine-1(2H)-carboxylate (6.5 g, 83% yield) as an oil. LCMS retention time 1.21 min [B]. MS (E−) m/z: 339 (M−H).

Intermediate T-1C: tert-butyl 4-(3-isopropyl-1H-indol-5-yl)piperidine-1-carboxylate

To a solution of tert-butyl 4-(3-isopropyl-1H-indol-5-yl)-5,6-dihydropyridine-1(2H)-carboxylate (7.9 g, 23.20 mmol) in ethyl acetate (150 mL), under a nitrogen atmosphere, was added palladium on carbon (0.617 g, 0.580 mmol). The vessel was pimp/purged three times with nitrogen gas then evacuated. Hydrogen gas was introduced via a balloon and the mixture was stirred at room temperature for 5 hours. The suspension was filtered through celite and the filtrate was concentrated to afford crude compound. The crude residue was purified by silica gel chromatography, eluting with 15% ethyl acetate in hexane. The combined fractions were collected and concentrated to afford tert-butyl 4-(3-isopropyl-1H-indol-5-yl)piperidine-1-carboxylate (6.5 g, 82% yield) as a white solid. LCMS retention time 2.48 min [C]. MS (E−) m/z: 341 (M−H).

Template 1: tert-butyl 4-(2-bromo-3-isopropyl-1H-indol-5-yl)piperidine-1-carboxylate

To a solution of tert-butyl 4-(3-isopropyl-1H-indol-5-yl)piperidine-1-carboxylate (6.3 g, 18.40 mmol) in DCE (60 mL), was added NBS (3.27 g, 18.40 mmol) dissolved in DCE (50 mL) drop wise via an addition funnel over 10 min at 0° C. The resulting brown solution was stirred at room temperature for 20 min. The reaction was quenched with sodium sulfite solution (15 mL). The volatiles were removed and the residue was taken up in DCM (50 mL) and the aqueous layer was separated. The organic layer was dried over Na₂SO₄ and concentrated to afford crude compound. The crude material was purified by silica gel chromatography. The compound eluted in 15% ethyl acetate in Pet ether, the fractions was collected and concentrated to afford tert-butyl 4-(2-bromo-3-isopropyl-1H-indol-5-yl)piperidine-1-carboxylate (6.4 g, 83% yield) as a white solid. LCMS retention time 2.58 min [H]. MS (E⁻) m/z: 367.2 (M−H).

Template 2: tert-butyl 4-(3-isopropyl-2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-indol-5-yl)piperidine-1-carboxylate

To a mixture of tert-butyl 4-(2-bromo-3-isopropyl-1H-indol-5-yl)piperidine-1-carboxylate (1.0 g, 2.373 mmol), 2-dicyclohexyphosphino-2′,6′-dimethoxybiphenyl (0.117 g, 0.285 mmol) and bis(benzonitrile)palladium(II)chloride (0.027 g, 0.071 mmol) in a 50 mL reaction tube was added dioxane (10 mL), the resulting reaction mixture was degassed for 10 min and then pinacolborane (0.456 g, 3.56 mmol) was added followed by dropwise addition of TEA (0.992 mL, 7.12 mmol). The solution was again degassed for 5 min. The resulting reaction mixture was heated at 85° C. for 3 h. The reaction mixture was concentrated and the crude residue was dissolved in ethyl acetate (100 mL), poured into a separatory funnel and was washed thoroughly with water (2×250 mL). The organic layer was dried over Na₂SO₄, filtered and the filtrate was concentrated under vacuum to afford the crude product. The residue was taken up in DCM (3 mL). The crude was purified by silica gel chromatography by eluting with 12% EtOAc/Pet ether. Following concentration of the fractions, the product was isolated as a white gummy product (0.75 g, 67.5% yield). LCMS retention time 4.27 min [H]. MS (E−) m/z: 467.3(M−H).

Fragments Fragment 1: 6-bromo-[1,2,4]triazolo[4,3-a]pyridine

Commercially available [108281-79-4].

Fragment 2: 6-bromo-3-methyl-[1,2,4]triazolo[4,3-a]pyridine

Commercially available [108281-78-3]

Fragment 3: 6-bromo-8-methyl-[1,2,4]triazolo[4,3-a]pyridine

Procedure A: A solution of 5-bromo-2-fluoro-3-methylpyridine (200 mg, 1.05 mmol) and hydrazine hydrate (0.26 mL, 5.26 mmol) in EtOH (2.1 mL) was sealed and stirred at 80° C. for 16 hours. Upon completion, the reaction mixture was cooled to room temperature and water (20 mL) was added. Precipitated solids were collected by vacuum filtration, triturated with water, and dried under vacuum to afford 5-bromo-2-hydrazono-3-methyl-1,2-dihydropyridine (152 mg, 0.752 mmol, 71.5% yield). This material (152 mg, 0.752 mmol) was suspended in dichloromethane (1.5 mL), and trimethylorthoformate (0.33 mL, 3.01 mmol) and TFA (58 μL, 0.752 mmol) were added sequentially. The reaction mixture was stirred at 25° C. for 1 hour. Upon completion, the reaction was quenched by addition of triethylamine (0.2 mL). The reaction mixture was concentrated. This crude material was purified by silica gel chromatography eluting with DCM/MeOH 100/0 to 85/15. Following concentration of the fractions, the product was isolated as an off-white solid 6-bromo-8-methyl-[1,2,4]triazolo[4,3-a]pyridine (85 mg, 0.401 mmol, 53.3% yield). LC retention time 0.58 min [TS1]. MS (ES⁺) m/z: 212.08 (M+H). ¹H NMR (400 MHz, CHLOROFORM-d) δ 8.76 (s, 1H), 8.17 (dd, J=1.5, 0.7 Hz, 1H), 7.16-7.08 (m, 1H), 2.72-2.65 (m, 3H).

Fragment 4: 6-bromo-7-methyl-[1,2,4]triazolo[4,3-a]pyridine

Prepared as in Procedure A starting from 5-bromo-2-fluoro-4-methylpyridine: LC retention time 0.54 min [TS1]. MS (ES⁺) m/z: 212.08 (M+H). ¹H NMR (400 MHz, CHLOROFORM-d) δ 8.73 (s, 1H), 8.37 (s, 1H), 7.63-7.60 (m, 1H), 2.46 (d, J=0.9 Hz, 3H).

Fragment 5: 6-bromo-5-methyl-[1,2,4]triazolo[4,3-a]pyridine

Prepared as in Procedure A starting from 3-bromo-6-fluoro-2-methylpyridine: LC retention time 0.55 min [TS1]. MS (ES⁺) m/z 212.08 (M+H). 1H NMR (400 MHz, CHLOROFORM-d) δ 8.76 (s, 1H), 7.59 (d, J=9.7 Hz, 1H), 7.40 (d, J=9.7 Hz, 1H), 2.80 (s, 3H).

Fragment 6: 6-bromo-8-methoxy-[1,2,4]triazolo[4,3-a]pyridine

Fragment 6 was prepared as in Procedure A starting from 5-bromo-2-fluoro-3-methoxypyridine: LC retention time 0.54 min [TS1]. MS (ES⁺) m/z 228.0 (M+H). ¹H NMR (400 MHz, CHLOROFORM-d) δ 8.74 (s, 1H), 7.94 (d, J=1.3 Hz, 1H), 6.55 (d, J=1.3 Hz, 1H), 4.08 (s, 3H).

Fragment 7: 6-bromo-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine

Procedure B: 5-bromo-3,4-dimethylpyridin-2-amine (1.00 g, 4.97 mmol) was suspended in concentrated hydrochloric acid (23 mL) and was cooled to −15° C. Sodium nitrite (1.72 g, 24.9 mmol) was added slowly and the reaction mixture was slowly warmed to 25° C. After 16 hours, the reaction was quenched by addition of water and dichloromethane. The layers were separated, and the aqueous layer was extracted with dichloromethane (3×25 mL). The combined organic layers were dried over sodium sulfate, filtered, and concentrated to afford a crude orange solid. This crude material was purified by silica gel chromatography eluting with hexanes/EtOAc 100/0 to 0/100. Following concentration of the fractions, the product was isolated as a clear oil 5-bromo-2-chloro-3,4-dimethylpyridine (709 mg, 3.22 mmol, 64.7% yield). LC retention time 0.97 min [TS1]. A portion of this material (354 mg, 1.61 mmol) was dissolved in DMSO (1.6 mL) and hydrazine hydrate (0.78 mL, 16.1 mmol) was added. The reaction vessel was sealed and heated to 130° C. for 8 hours. Upon completion, the reaction mixture was cooled to 25° C. Water (20 mL) and 4/1 chloroform/isopropanol (20 mL) were added. The layers were separated, and the aqueous layer was extracted with 4/1 chloroform/isopropanol (3×25 mL). The combined organic layers were washed with water (3×25 mL), dried over sodium sulfate, filtered, and concentrated to afford a crude white solid. This crude material was purified by silica gel chromatography eluting with DCM/MeOH 100/0 to 90/10. Following concentration of the fractions, the product was isolated as a white solid 6-bromo-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (203 mg, 0.896 mmol, 55.8% yield). LC retention time 0.56 min [TS1]. MS (ES⁺) m/z 226.0 (M+H). ¹H NMR (400 MHz, CHLOROFORM-d) δ 8.71 (s, 1H), 8.25 (s, 1H), 2.70 (s, 3H), 2.43 (s, 3H).

Fragment 8: 6-bromo-5,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine

Fragment 8 was prepared as in procedure B starting from 5-bromo-3,6-dimethylpyridin-2-amine: LC retention time 0.60 min [TS1]. MS (ES⁺) m/z 226.0 (M+H).

Fragment 9: 6-bromo-8-chloro-7-methyl-[1,2,4]triazolo[4,3-a]pyridine

A solution of 5-bromo-4-methylpyridin-2-amine (500 mg, 2.67 mmol) in DMF (5 mL) was cooled to 0° C. N-Chlorosuccinimide (357 mg, 2.67 mmol) was added. After stirring at 0° C. for 1 hour, the reaction was quenched by the addition of water (20 mL) and DCM (20 mL). The aqueous layer was extracted with DCM (3×5 mL) and the combined organic layers were washed with water (3×10 mL). The combined organic layers were dried over sodium sulfate, filtered, and concentrated. The crude isolate was purified via silica gel chromatography eluting in DCM/MeOH from 100/0 to 90/10 to afford 5-bromo-3-chloro-4-methylpyridin-2-amine (640 mg, 99% yield). This material was carried through procedure B as detailed above to afford Fragment 9 (F-9). LC retention time 0.64 min [TS1]. MS (ES⁺) m/z 246.08 (M+H). ¹H NMR (400 MHz, CHLOROFORM-d) δ 8.77 (s, 1H), 8.31 (s, 1H), 2.61 (s, 1H).

Fragment 10: 6-bromo-3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine

Procedure C: A solution of 5-bromo-2-fluoro-3-methylpyridine (440 mg, 2.32 mmol) and hydrazine hydrate (0.56 mL, 11.6 mmol) in EtOH (4.6 mL) was sealed and stirred at 80° C. for 41 hours. Upon completion, the reaction mixture was cooled to room temperature and water (20 mL) was added. Precipitated solids were collected by vacuum filtration, triturated with water, and dried under vacuum to afford 5-bromo-2-hydrazono-3-methyl-1,2-dihydropyridine (405 mg, 2.00 mmol, 87% yield). This material (405 mg, 2.00 mmol) was suspended in DCM (4.0 mL), and trimethylorthoacetate (1.47 mL, 8.02 mmol) and TFA (0.15 mL, 2.00 mmol) were added sequentially. The reaction mixture was stirred at 25° C. for 1 hour. Upon completion, the reaction was quenched via addition of Et₃N (0.4 mL). The reaction mixture was concentrated. This crude material was purified via silica gel chromatography eluting with DCM/MeOH 100/0 to 90/10. Following concentration of the fractions, the product was isolated as an off-white solid 6-bromo-3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (305 mg, 1.35 mmol, 67.3% yield). LC retention time 0.54 min [TS1]. MS (ES⁺) m/z 226.0 (M+H). ¹H NMR (400 MHz, CHLOROFORM-d) δ 7.90-7.87 (m, 1H), 7.11-7.06 (m, 1H), 2.73 (s, 3H), 2.68-2.65 (m, 3H).

Fragment 11: 6-bromo-3-(methoxymethyl)-[1,2,4]triazolo[4,3-a]pyridine

Procedure D: A solution of 5-bromo-2-fluoropyridine (500 mg, 2.84 mmol) and hydrazine hydrate (690 μl, 14.21 mmol) in EtOH (5682 μl) was sealed and stirred at 90° C. for 4 hours. Upon completion, the reaction mixture was cooled to room temperature and water was added to form a precipitate. This precipitate was collected by vacuum filtration, triturated with water, and dried under vacuum to obtain the desired product 5-bromo-2-hydrazono-1,2-dihydropyridine (360 mg, 1.92 mmol, 67.4% yield). A portion of this material (100 mg, 0.532 mmol) was dissolved in DMF (2.5 mL). 2-Methoxyacetic acid (71.9 mg, 0.798 mmol), triethylamine (0.22 mL, 1.60 mmol), and 50% T3P in DMF (0.47 mL, 0.798 mmol) were added sequentially and the reaction mixture was stirred at 25° C. for 1 hour. Upon completion, the reaction was quenched via addition of water (10 mL) and dichloromethane (10 mL). The layers were separated and the aqueous layer was extracted with dichloromethane (3×10 mL). The combined organics were washed with water (3×20 mL), dried over sodium sulfate, filtered, and concentrated to afford N′-(5-bromopyridin-2(1H)-ylidene)-2-methoxyacetohydrazide as a crude oil which was carried forward without additional purification and considered quantitative for the subsequent step. This material (0.532 mmol) was suspended in toluene (1.8 mL) and acetic acid (0.37 mL, 6.38 mmol) was added. The reaction vessel was sealed and heated to 110° C. for 43 hours. The reaction mixture was concentrated, dissolved in dichloromethane (20 mL), and washed with water (3×10 mL). The layers were separated and the organic layer was dried over sodium sulfate, filtered, and concentrated to afford a crude tan oil. This crude material was purified via silica gel chromatography eluting with DCM/MeOH 100/0 to 80/20. Following concentration of the fractions, solid product was isolated 6-bromo-3-(methoxymethyl)-[1,2,4]triazolo[4,3-a]pyridine (57 mg, 0.235 mmol, 44.3% yield). LC retention time 0.57 min [TS1]. MS (ES⁺) m/z 241.9 (M+H). ¹H NMR (400 MHz, CHLOROFORM-d) δ 8.38 (dd, J=1.7, 1.0 Hz, 1H), 7.66 (dd, J=9.7, 0.9 Hz, 1H), 7.33 (dd, J=9.7, 1.8 Hz, 1H), 4.98 (s, 2H), 3.38 (s, 3H).

EXAMPLE 1 6-(3-isopropyl-5-(piperidin-4-yl)-1H-indol-2-yl)-[1,2,4]triazolo[4,3-a]pyridine

Intermediate 1A: tert-butyl 4-(2-([1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-isopropyl-1H-indol-5-yl)piperidine-1-carboxylate

To a solution of Template 2 (250 mg, 0.534 mmol), Fragment 1 (159 mg, 0.801 mmol), and [1,1′-bis(diphenylphosphino)ferrocene]palladium(II) dichloride (39.1 mg, 0.053 mmol) in dioxane (3.6 mL) was added 2M K₃PO₄ in water (0.80 mL, 1.60 mmol). The biphasic mixture was degassed with nitrogen for 10 min. The vial was sealed and stirred at 90° C. for 2.5 hours. Upon completion, the reaction mixture was cooled to 25° C. The reaction mixture was diluted with water and precipitated solids were collected by vacuum filtration. The solid was triturated with isopropanol and ether to afford tert-butyl 4-(2-([1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-isopropyl-1H-indol-5-yl)piperidine-1-carboxylate (237 mg, 0.516 mmol, 97% yield) as an off-white powder. LCMS retention time 0.95 min [TS1]. MS (ES⁺) m/z: 460.08 (M+H). ¹H NMR (400 MHz, DMSO-d₆): 11.11 (s, 1H), 9.35 (s, 1H), 8.66 (s, 1H), 7.90 (d, J=9.2 Hz, 1H), 7.55 (s, 1H), 7.50 (d, J=10.1 Hz, 1H), 7.30 (d, J=8.1 Hz, 1H), 7.02 (d, J=7.5 Hz, 1H), 4.10 (d, J=10.8 Hz, 2H), 3.25 (s, 1H), 2.94-2.69 (m, 3H), 1.80 (d, J=13.4 Hz, 2H), 1.65-1.48 (m, 2H), 1.47-1.38 (m, 15H).

Example 1:

To a solution of tert-butyl 4-(2-([1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-isopropyl-1H-indol-5-yl)piperidine-1-carboxylate (237 mg, 0.516 mmol) in CH₂Cl₂ (10 mL) at 25° C. was added a 4 M solution of HCl in dioxane (2.58 mL, 10.3 mmol). The reaction mixture was stirred at 25° C. for 2 hours. Upon completion, the reaction mixture was concentrated. The bulk of this material was considered quantitative and carried forward as is for subsequent reactions. A small amount was purified using the following method: Column: XBridge C18, 19×200 mm, 5-μm particles; Mobile Phase A: 5:95 acetonitrile:water with 10-mM ammonium acetate; Mobile Phase B: 95:5 acetonitrile:water with 10-mM ammonium acetate; Gradient: 0-100% B over 15 minutes, then a 5-minute hold at 100% B; Flow: 20 mL/min. Fractions containing the product were combined and dried via centrifugal evaporation. LCMS retention time 0.55 min [TS1]. MS (ES⁺) m/z: 360.5 (M+H). ¹H NMR (500 MHz, DMSO-d₆) δ 11.15 (s, 1H), 9.34 (s, 1H), 8.65 (s, 1H), 7.90 (d, J=9.5 Hz, 1H), 7.54 (s, 1H), 7.50 (d, J=9.6 Hz, 1H), 7.31 (d, J=8.3 Hz, 1H), 7.01 (d, J=8.4 Hz, 1H), 3.34-3.20 (m, 1H), 3.15 (d, J=7.3 Hz, 2H), 2.82-2.66 (m, 3H), 1.81 (br. s., 3H), 1.75-1.62 (m, 2H), 1.42 (d, J=6.9 Hz, 6H).

The examples in Table 1 were prepared according to the general procedure for Example 1 using the indicated fragment.

TABLE 1 Ex. LCMS Rt HPLC No. Structure Fragment [M + H] (min) Method 2

F-3 374.3 0.88 QC-ACN- TFA-XB 3

F-2 374.3 0.95 QC-ACN- AA-XB 4

F-4 374.2 0.94 QC-ACN- AA-XB 5

F-5 374.3 0.94 QC-ACN- AA-XB 6

 F-10 388.3 1.03 QC-ACN- AA-XB 7

 F-11 404 1.25 QC-ACN- AA-XB 8

F-7 388.1 0.93 QC-ACN- AA-XB 9

F-8 388 1.26 QC-ACN- AA-XB 10

F-9 408.3 1.03 QC-ACN- AA-XB 11

F-6 390.2 0.93 QC-ACN- AA-XB

EXAMPLE 12 2-(4-(3-isopropyl-2-(8-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1H-indol-5-yl)piperidin-1-yl)-N,N-dimethylacetamide

Method A: To 6-(3-isopropyl-5-(piperidin-4-yl)-1H-indol-2-yl)-8-methyl-[1,2,4] triazolo[4,3-a]pyridine (14.8 mg, 0.0397 mmol) in DMF (0.5 mL) were added DBU (0.036 mL, 0.238 mmol) and 2-chloro-N,N-dimethylacetamide (0.012 mL, 0.119 mmol). The reaction mixture was stirred at 25° C. When all starting materials were consumed, water (0.025 mL) and DMF (1 mL) were added. The reaction mixture was purified using the following method: Column: XBridge C18, 19×200 mm, 5-μm particles; Mobile Phase A: 5:95 acetonitrile:water with 10-mM ammonium acetate; Mobile Phase B: 95:5 acetonitrile:water with 10-mM ammonium acetate; Gradient: 10-50% B over 20 minutes, then a 4-minute hold at 100% B; Flow: 20 mL/min. Fractions containing the product were combined and dried via centrifugal evaporation to afford 2-(4-(3-isopropyl-2-(8-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1H-indol-5-yl)piperidin-1-yl)-N,N-dimethylacetamide (5.8 mg, 0.012 mmol, 30.6% yield). LCMS retention time 0.96 [QC-ACN-TFA-XB]. MS (ES⁺) m/z: 459.4 (M+H). ¹H NMR (500 MHz, DMSO-d₆) δ 11.07 (s, 1H), 9.30 (s, 1H), 8.48 (s, 1H), 7.53 (s, 1H), 7.33-7.22 (m, 2H), 7.01 (br d, J=8.4 Hz, 1H), 3.24 (dt, J=13.7, 6.6 Hz, 1H), 3.19-3.15 (m, 2H), 3.04 (s, 3H), 2.95 (br d, J=10.9 Hz, 2H), 2.81 (s, 3H), 2.60 (s, 3H), 2.18 (br t, J=10.0 Hz, 2H), 1.81-1.66 (m, 4H), 1.40 (br d, J=6.9 Hz, 6H).

The examples in Table 2 were prepared in according to the general procedure for Example 12 using the indicated example.

TABLE 2 Ex. LCMS Rt HPLC No. Structure Template [M +H] (min) Method 13

Ex 1 431 0.96 QC- ACN- AA- XB 14

Ex 1 445.4 0.89 QC- ACN- TFA- XB 15

Ex 4 445.5 0.83 QC- ACN- TFA- XB 16

Ex 2 445 1.31 OC- ACN- AA- XB 17

Ex 3 445.4 0.85 QC- ACN- TFA- XB 18

Ex 4 459 1.14 QC- ACN- AA- XB 19

Ex 3 459.2 1.14 QC- ACN- AA- XB 20

Ex 4 469.2 1.39 QC- ACN- AA- XB 21

Ex 2 469.4 0.93 QC- ACN- TFA- XB 22

Ex 3 469 1.38 QC- ACN- AA- XB 23

Ex 1 455.2 0.78 QC- ACN- TFA- XB 24

Ex 5 445.2 0.79 QC- ACN- TFA- XB 25

Ex 5 459.4 1.17 QC- ACN- AA- XB 26

Ex 5 469 0.82 QC- ACN- TFA- XB 27

Ex 2 432.3 1.21 QC- ACN- AA- XB 28

Ex 2 418.3 1.05 QC- ACN- TFA- XB 29

Ex 2 457.8 0.96 QC- ACN- TFA- XB 30

Ex 2 444.1 1.09 QC- ACN- AA- XB 31

Ex 6 427 1.65 QC- ACN- AA- XB 32

Ex 6 494.4 1.5 QC- ACN- AA- XB 33

Ex 6 483 1.25 QC- ACN- AA- XB 34

Ex 6 473.4 1.3 QC- ACN- AA- XB 35

Ex 2 480.4 0.93 QC- ACN- TFA- XB 36

Ex 2 484.3 1.76 QC- ACN- AA- XB 37

Ex 2 413.2 0.98 QC- ACN- TFA- XB 38

Ex 7 489 1.42 QC- ACN- AA- XB 39

Ex 8 472.9 1.09 QC- ACN- TFA- XB 40

Ex 9 483.1 1.19 QC- ACN- TFA- XB 41

Ex 9 498.1 1.56 QC- ACN- AA- XB 42

Ex 9 473.3 1.05 QC- ACN- TFA- XB 43

Ex 8 493.9 1.56 QC- ACN- AA- XB 44

Ex 8 498 1.91 QC- ACN- AA- XB 45

Ex 8 483.3 1.47 QC- ACN- AA- XB 46

 Ex 10 514.2 1.49 QC- ACN- AA- XB 47

 Ex 10 503.2 1.25 QC- ACN- AA- XB 48

 Ex 10 518 2.06 QC- ACN- AA- XB 49

 Ex 10 493 1.56 QC- ACN- AA- XB 50

 Ex 10 447.2 1.19 QC- ACN- TFA- XB 51

Ex 8 427.2 1.03 QC- ACN- TFA- XB 52

Ex 8 535.2 1.29 QC- ACN- AA- XB 53

 Ex 10 555 1.25 QC- ACN- TFA- XB 54

 Ex 11 475.2 1.25 QC- ACN- AA- XB 55

 Ex 11 499.9 1.59 QC- ACN- AA- XB 56

Ex 8 501.2 1.2 QC- ACN- AA- XB 57

Ex 8 499.3 1.06 QC- ACN- TFA- XB

EXAMPLE 58 1-(4-(3-isopropyl-2-(8-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1H-indol-5-yl)piperidin-1-yl)-2-methylpropan-2-ol

6-(3-isopropyl-5-(piperidin-4-yl)-1H-indol-2-yl)-8-methyl-[1,2,4]triazolo[4,3-a] pyridine, HCl (29.2 mg, 0.0712 mmol) was suspended in MeOH (1 mL). 2,2-dimethyloxirane (0.019 mL, 0.214 mmol) and K₂CO₃ (59.0 mg, 0.427 mmol) were added and the reaction vessel was sealed. The reaction mixture was stirred for 3 hours at 80° C. Upon completion, the reaction mixture was diluted with DMF (0.9 mL), water (0.025 mL), and purified using the following method: Column: XBridge C18, 19×200 mm, 5-μm particles; Mobile Phase A: 5:95 acetonitrile:water with 10-mM ammonium acetate; Mobile Phase B: 95:5 acetonitrile:water with 10-mM ammonium acetate; Gradient: 15-55% B over 19 minutes, then a 5-minute hold at 100% B; Flow: 20 mL/min. Fractions containing the product were combined and dried via centrifugal evaporation. The material was further purified via preparative LC/MS with the following conditions: Column: XBridge C18, 19×200 mm, 5-μm particles; Mobile Phase A: 5:95 acetonitrile:water with 0.1% trifluoroacetic acid; Mobile Phase B: 95:5 acetonitrile:water with 0.1% trifluoroacetic acid; Gradient: 10-35% B over 25 minutes, then a 2-minute hold at 35% B; Flow: 20 mL/min. Fractions containing the product were combined and dried via centrifugal evaporation to afford 1-(4-(3-isopropyl-2-(8-methyl-[1,2,4]triazolo[4,3-a] pyridin-6-yl)-1H-indol-5-yl)piperidin-1-yl)-2-methylpropan-2-ol, TFA (12.0 mg, 0.021 mmol, 30.1% yield). LCMS retention time 0.98 [QC-ACN-TFA-XB]. MS (ES⁺) m/z: 446.2 (M+H). ¹H NMR (500 MHz, DMSO-d₆) δ 11.15 (s, 1H), 9.33 (s, 1H), 8.51 (s, 1H), 7.57 (s, 1H), 7.36-7.29 (m, 2H), 7.02 (br d, J=8.4 Hz, 1H), 3.70 (br d, J=10.5 Hz, 1H), 3.32-3.09 (m, 5H), 2.88 (br t, J=11.7 Hz, 1H), 2.61 (s, 3H), 2.29-2.02 (m, 2H), 2.00-1.87 (m, 2H), 1.43 (br d, J=6.9 Hz, 6H), 1.28 (s, 6H).

The examples in Table 3 were prepared according to the general procedure for Example 58 using the indicated example.

TABLE 3 Ex. LCMS Rt HPLC No. Structure Template [M + H] (min) Method 59

Ex 9  460.1 1.51 QC- ACN- AA- XB 60

Ex 8  460.4 1.21 QC- ACN- AA- XB 61

Ex 10 480 1.24 QC- ACN- AA- XB 62

Ex 11 462 1.24 QC- ACN- AA- XB

EXAMPLE 63 6-(3-isopropyl-5-(1-(oxetan-3-yl)piperidin-4-yl)-1H-indol-2-yl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridine

Method B: To a solution of 6-(3-isopropyl-5-(piperidin-4-yl)-1H-indol-2-yl)-8-methyl-[1,2,4] triazolo[4,3-a]pyridine, HCl (0.050 g, 0.090 mmol), oxetan-3-one (0.016 mL, 0.271 mmol) and triethylamine (0.013 mL, 0.090 mmol) in DMF (1 mL) at 25° C. was added sodium triacetoxyborohydride (75 mg, 0.354 mmol). The reaction mixture was stirred at 25° C. for 4 hours. When starting material was fully consumed, the reaction was quenched via the addition of water (0.025 mL) and DMF (0.9 mL). The material was purified using the following method: Column: XBridge C18, 19×200 mm, 5-μm particles; Mobile Phase A: 5:95 acetonitrile:water with 10-mM ammonium acetate; Mobile Phase B: 95:5 acetonitrile:water with 10-mM ammonium acetate; Gradient: 15-55% B over 20 minutes, then a 5-minute hold at 100% B; Flow: 20 mL/min. Fractions containing the product were combined and dried via centrifugal evaporation to afford 6-(3-isopropyl-5-(1-(oxetan-3-yl)piperidin-4-yl)-1H-indol-2-yl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridine (14.5 mg, 0.034 mmol, 37.4% yield). LCMS retention time 0.87 [QC-ACN-TFA-XB]. MS (ES⁺) m/z: 429.9 (M+H). ¹H NMR (500 MHz, DMSO-d₆) δ 11.08 (s, 1H), 9.31 (s, 1H), 8.49 (s, 1H), 7.54 (s, 1H), 7.36-7.24 (m, 2H), 7.02 (br d, J=8.2 Hz, 1H), 4.58-4.52 (m, 2H), 4.46 (br t, J=6.0 Hz, 2H), 3.42 (br t, J=5.8 Hz, 1H), 3.25 (dt, J=13.9, 6.9 Hz, 1H), 2.81 (br d, J=10.4 Hz, 2H), 2.60 (s, 3H), 1.95-1.84 (m, 2H), 1.82-1.65 (m, 4H), 1.41 (br d, J=6.9 Hz, 6H).

The examples in Table 4 were prepared according to the general procedure for Example 63 using the indicated example.

TABLE 4 Ex. LCMS Rt HPLC No. Structure Template [M + H] (min) Method 64

Ex 1 444.2 0.85 QC- ACN- TFA- XB 65

Ex 1 416.2 1.38 QC- ACN- AA-XB 66

Ex 4 430.3 0.84 QC- ACN- TFA- XB 67

Ex 3 430.4 0.84 QC- ACN- TFA- XB 68

Ex 4 458 1.12 QC- ACN- AA-XB 69

Ex 2 458.2 1.15 QC- ACN- AA-XB 70

Ex 5 458 1.12 QC- ACN- AA-XB 71

Ex 6 482.4 1.32 QC- ACN- AA-XB 72

Ex 6 444.4 1.57 QC- ACN- AA-XB 73

Ex 6 472 1.2 QC- ACN- AA-XB 74

Ex 2 468 1.24 QC- ACN- AA-XB 75

Ex 8 444.4 1.49 QC- ACN- AA-XB 76

Ex 9 444.4 1.72 QC- ACN- AA-XB 77

Ex 9 471.9 1.13 QC- ACN- AA-XB 78

Ex 8 472.3 1.52 QC- ACN- AA-XB 79

Ex 8 472 1.34 QC- ACN- AA-XB 80

 Ex 10 492 1.44 QC- ACN- AA-XB 81

 Ex 10 492 1.19 QC- ACN- AA-XB 82

 Ex 10 463.9 1.63 QC- ACN- AA-XB 83

Ex 8 483.4 0.9 QC- ACN- TFA- XB 84

 Ex 10 503 1.39 QC- ACN- AA-XB 85

Ex 8 500.4 1.14 QC- ACN- TFA- XB 86

 Ex 11 446.2 1.51 QC- ACN- AA-XB 87

Ex 8 500.4 1.51 QC- ACN- AA-XB 88

 Ex 11 474.3 1.11 QC- ACN- AA-XB 89

Ex 8 510.3 1.11 QC- ACN- TFA- XB 90

 Ex 11 474.2 1.08 QC- ACN- TFA- XB 91

Ex 8 494.4 1.58 QC- ACN- AA-XB 92

Ex 8 500.3 1.17 QC- ACN- TFA- XB 93

Ex 8 458 1.39 QC- ACN- AA-XB 94

Ex 11 460.2 1.39 QC- ACN- AA-XB 95

Ex 11 508.3 1.49 QC- ACN- AA-XB 96

Ex 11 404 0.93 QC- ACN- TFA- XB 97

Ex 11 432.1 1.14 QC- ACN- AA-XB 98

Ex 8 402.1 1.03 QC- ACN- AA-XB 99

Ex 8 430.1 1.04 QC- ACN- TFA- XB 100

Ex 8 528.3 1.56 QC- ACN- AA-XB 101

Ex 8 506.2 1.44 QC- ACN- AA-XB 102

Ex 8 458.3 0.64 TS 1 103

Ex 8 458.4 0.63 TS 1

EXAMPLE 104 2-(dimethylamino)-1-(4-(3-isopropyl-2-(8-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1H-indol-5-yl)piperidin-1-yl)ethanone

Method C: To a solution of 6-(3-isopropyl-5-(piperidin-4-yl)-1H-indol-2-yl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridine, HCl (16.28 mg, 0.0397 mmol), 2-(dimethylamino)acetic acid (8.19 mg, 0.079 mmol), and Et₃N (0.033 mL, 0.238 mmol) in DMF (0.5 mL) at 25° C. was added 50% T3P in DMF (0.093 mL, 0.159 mmol). The reaction mixture was stirred at 25° C. for 3 days. Upon completion, the reaction mixture was diluted with water (0.025 mL) and DMF (0.9 mL). The product was purified using the following method: Column: XBridge C18, 19×200 mm, 5-μm particles; Mobile Phase A: 5:95 acetonitrile:water with 10-mM ammonium acetate; Mobile Phase B: 95:5 acetonitrile:water with 10-mM ammonium acetate; Gradient: 10-50% B over 20 minutes, then a 2-minute hold at 100% B; Flow: 20 mL/min. Fractions containing the product were combined and dried via centrifugal evaporation to afford 2-(dimethylamino)-1-(4-(3-isopropyl-2-(8-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1H-indol-5-yl)piperidin-1-yl)ethanone (7.5 mg, 0.016 mmol, 41.2% yield). LCMS retention time 0.95 [QC-ACN-TFA-XB]. MS (ES⁺) m/z: 459.0 (M+H). ¹H NMR (500 MHz, DMSO-d₆) δ 11.08 (s, 1H), 9.29 (s, 1H), 8.47 (s, 1H), 7.52 (s, 1H), 7.33-7.27 (m, 2H), 6.99 (br d, J=8.5 Hz, 1H), 4.49 (br d, J=12.7 Hz, 1H), 4.12 (br d, J=12.6 Hz, 1H), 3.23 (dt, J=13.9, 7.0 Hz, 1H), 3.18-3.03 (m, 3H), 2.89-2.78 (m, 1H), 2.64 (br t, J=12.5 Hz, 1H), 2.59 (s, 3H), 2.19 (s, 6H), 1.89-1.77 (m, 2H), 1.70-1.57 (m, 1H), 1.51-1.42 (m, 1H), 1.39 (br d, J=6.9 Hz, 6H).

The examples in Table 5 were prepared according to the general procedure for Example 104 using the indicated example.

TABLE 5 Ex. LCMS Rt HPLC No. Structure Template [M + H] (min) Method 105

Ex 1 445.3 1.1 QC- ACN- AA-XB 106

Ex 3 459 1.11 QC- ACN- AA-XB 107

Ex 4 459.4 1.16 QC- ACN- AA-XB 108

Ex 5 459.4 1.15 QC- ACN- AA-XB

EXAMPLE 109 6-(5-(2,6-dimethylpiperidin-4-yl)-3-isopropyl-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine

Intermediate 109A: 5-chloro-3-isopropyl-1H-indole

Intermediate 109A was prepared according to the general procedure for T-1A starting from 5-chloro-1-H-indole. LC retention time 1.02 min [TS1]. MS (ES⁺) m/z 194.2 (M+H). ¹H NMR (400 MHz, CHLOROFORM-d) δ 7.92 (br s, 1H), 7.62 (d, J=2.0 Hz, 1H), 7.29-7.24 (m, 1H), 7.14 (dd, J=8.6, 2.0 Hz, 1H), 6.99 (d, J=2.0 Hz, 1H), 3.24-3.10 (m, 1H), 1.36 (d, J=6.8 Hz, 6H).

Intermediate 109B: 2-bromo-5-chloro-3-isopropyl-1H-indole

Intermediate 109B was prepared according to the general procedure for Template 1 starting from 5-chloro-3-isopropyl-1H-indole. LC retention time 1.08 min [TS1]. MS (ES⁺) m/z 272.0 (M+H). ¹H NMR (400 MHz, CHLOROFORM-d) δ 7.93 (br. s., 1H), 7.67-7.60 (m, 1H), 7.22-7.15 (m, 1H), 7.12-7.07 (m, 1H), 3.20 (quin, J=7.1 Hz, 1H), 1.40 (d, J=7.0 Hz, 6H).

Intermediate 109C: 5-chloro-3-isopropyl-2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-indole

Intermediate 109C was prepared according to the general procedure for Template 2 starting from 2-bromo-5-chloro-3-isopropyl-1H-indole. Material obtained was estimated to be 45% pure. LC retention time 1.18 min [TS1]. MS (ES⁺) m/z 320.2 (M+H).

Intermediate 109D: 6-(5-chloro-3-isopropyl-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine

To a solution of 5-chloro-3-isopropyl-2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-indole (45% purity, 1428 mg, 2.01 mmol), Fragment 7 (500 mg, 2.21 mmol), and PdCl₂(dppf) (73.6 mg, 0.101 mmol) in dioxane (13.4 mL) was added 3M K₃PO₄ in water (2.01 mL, 6.03 mmol). The biphasic mixture was degassed with nitrogen. The reaction vessel was sealed and the reaction mixture was stirred at 90° C. for 1.5 hours. Upon completion, the reaction mixture was cooled to room temperature and concentrated. The crude material was purified on silica gel eluting with 100% DCM to 85% DCM/15% MeOH to afford 6-(5-chloro-3-isopropyl-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (491 mg, 1.45 mmol, 72.1% yield). LCMS retention time 0.87 [TS1]. MS (ES⁺) m/z: 339.1 (M+H).

Intermediate 109E: Tert-butyl 4-(2-(7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-isopropyl-1H-indol-5-yl)-2,6-dimethyl-5,6-dihydropyridine-1(2H)-carboxylate

To a solution of 6-(5-chloro-3-isopropyl-1H-indol-2-yl)-7,8-dimethyl-[1,2,4] triazolo[4,3-a]pyridine (126 mg, 0.371 mmol), tert-butyl 2,6-dimethyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-5,6-dihydropyridine-1(2H)-carboxylate (125 mg, 0.371 mmol) (mixture of diastereomers), and 2M K₃PO₄ in water (371 μl, 1.11 mmol) in dioxane (2.47 mL) was added PdCl₂(dppf) (14.6 mg, 0.019 mmol). The biphasic mixture was degassed with nitrogen. The reaction vessel was sealed. The reaction mixture was stirred at 90° C. for 2 hours. Upon completion, the reaction mixture was cooled to room temperature and concentrated. The crude material was purified on silica gel eluting with 100% DCM to 85% DCM/15% MeOH to afford tert-butyl 4-(2-(7,8-dimethyl-[1,2,4] triazolo[4,3-a]pyridin-6-yl)-3-isopropyl-1H-indol-5-yl)-2,6-dimethyl-5,6-dihydropyridine-1(2H)-carboxylate (150 mg, 0.292 mmol, 79% yield). LCMS retention time 0.97 [TS1]. MS (ES⁺) m/z: 514.3 (M+H).

Intermediate 109F: tert-butyl4-(2-(7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-isopropyl-1H-indol-5-yl)-2,6-dimethylpiperidine-1-carboxylate

To a solution of tert-butyl 4-(2-(7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-isopropyl-1H-indol-5-yl)-2,6-dimethyl-5,6-dihydropyridine-1(2H)-carboxylate (300 mg, 0.584 mmol) in MeOH (12 mL) in a Parr shaker was added with 10% palladium on carbon (124 mg, 0.116 mmol). The reaction vessel was charged with 50 PSI of hydrogen gas and shaken for 17 hours at room temperature. Upon completion, the reaction mixture was filtered through celite, and the filtrate was concentrated to afford tert-butyl 4-(2-(7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-isopropyl-1H-indol-5-yl)-2,6-dimethylpiperidine-1-carboxylate (235 mg, 0.456 mmol, 78% yield) a mixture of diastereomers. The isolated material was carried forward without additional purification. LCMS retention time 1.00 [TS1]. MS (ES⁺) m/z: 516.3 (M+H).

Example 109:

To a solution of tert-butyl 4-(2-(7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-isopropyl-1H-indol-5-yl)-2,6-dimethylpiperidine-1-carboxylate (235 mg, 0.456 mmol) in DCM (9.0 mL) at room temperature was added HCl in dioxane, 4M (2.28 mL, 9.11 mmol). The reaction mixture was stirred at room temperature for 3.5 hours. The reaction mixture was concentrated to afford 6-(5-(2,6-dimethylpiperidin-4-yl)-3-isopropyl-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine, HCl (196 mg, 0.434 mmol, 95% yield) as a mixture of isomers. The crude material from this reaction was carried forward without additional purification and derivatized to obtain the compounds listed in Table 6. LCMS retention time 0.66 [TS1]. MS (ES⁺) m/z: 416.3 (M+H).

The examples in Table 6 were prepared using Example 109 with one of the General Methods listed above.

TABLE 6 Ex. General LCMS Rt HPLC No. Structure Method [M + H] (min) Method 110

A 522.1 1.46 QC- ACN- AA-XB 111

A 522 1 QC- ACN- TFA-XB 112

A 501.5 1.05 QC- ACN- TFA-XB 113

B 500.5 1.06 QC- ACN- TFA-XB 114

B 500.6 1.02 QC- ACN- TFA-XB 115

B 472.1 1.18 QC- ACN- AA-XB

EXAMPLES 116 AND 117 6-(5-(8-azabicyclo[3.2.1]octan-3-yl)-3-isopropyl-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine

Intermediate 116A: Tert-butyl 3-(2-(7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-isopropyl-1H-indol-5-yl)-8-azabicyclo[3.2.1]oct-3-ene-8-carboxylate

To a solution of 6-(5-chloro-3-isopropyl-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (Intermediate 109D, 135 mg, 0.398 mmol), tert-butyl 3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-8-azabicyclo[3.2.1]oct-3-ene-8-carboxylate (racemate) (160 mg, 0.478 mmol), and XPhos G2 precatalyst (31.3 mg, 0.040 mmol) in dioxane (2.65 mL) was added 2M K₃PO₄ in water (398 μl, 1.195 mmol). The biphasic mixture was degassed with nitrogen. The reaction vessel was sealed and stirred at 90° C. for 1.5 hours. Upon completion, the reaction mixture was cooled to room temperature and concentrated. The crude material was purified on silica gel eluting in 100% DCM to 85%/15% DCM/MeOH to afford tert-butyl 3-(2-(7,8-dimethyl-[1,2,4]triazolo[4,3-a] pyridin-6-yl)-3-isopropyl-1H-indol-5-yl)-8-azabicyclo[3.2.1]oct-3-ene-8-carboxylate. LCMS retention time 0.94 [TS1]. MS (ES⁺) m/z: 512.3 (M+H).

Intermediate 116B: Tert-butyl 3-(2-(7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-isopropyl-1H-indol-5-yl)-8-azabicyclo[3.2.1]octane-8-carboxylate

To a solution of tert-butyl 3-(2-(7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-isopropyl-1H-indol-5-yl)-8-azabicyclo[3.2.1]oct-3-ene-8-carboxylate (116 mg, 0.227 mmol) in MeOH (2.27 mL) and DCM (2.27 mL) was added 10% palladium on carbon (72.4 mg, 0.069 mmol). The reaction vessel was charged with hydrogen gas at 50 PSI and shaken on the Parr hydrogenation apparatus for 19 hours. The catalyst was filtered off, and the reaction mixture was concentrated. The crude residue was redissolved in MeOH (6.0 mL) and fresh 10% palladium on carbon (24.1 mg, 0.023 mmol) was added. The reaction vessel was charged with hydrogen gas at 50 PSI and shaken on the Parr hydrogenation apparatus for 3 hours. Upon completion, the reaction mixture was filtered and concentrated to afford tert-butyl 3-(2-(7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-isopropyl-1H-indol-5-yl)-8-azabicyclo[3.2.1]octane-8-carboxylate (95 mg, 0.185 mmol, 82% yield, mixture of isomers). LCMS retention time 0.95 [TS1]. MS (ES⁺) m/z: 514.3 (M+H).

Intermediate 116C: 6-(5-(8-azabicyclo[3.2.1]octan-3-yl)-3-isopropyl-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine, HCl

To a solution of tert-butyl 3-(2-(7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-isopropyl-1H-indol-5-yl)-8-azabicyclo[3.2.1]octane-8-carboxylate (95 mg, 0.185 mmol) in DCM (3.70 mL) at room temperature was added 4M HCl in dioxane (0.93 mL, 3.70 mmol). The reaction mixture was stirred at room temperature for 1.5 hours. Upon completion, the reaction mixture was concentrated to afford 6-(5-(8-azabicyclo[3.2.1] octan-3-yl)-3-isopropyl-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine, HCl (83 mg, 0.185 mmol, 100% yield, mixture of isomers). LCMS retention time 0.65, 0.66 [TS1]. MS (ES⁺) m/z: 414.4, 414.3 (M+H). The majority of this mixture of isomers was carried forward as is for derivatization and resolved into individual isomers to yield the examples listed in Table 7 after subsequent reaction.

Examples 116 and 117:

A small portion of the 6-(5-(8-azabicyclo[3.2.1]octan-3-yl)-3-isopropyl-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine, HCl was purified to resolve the individual isomers via preparative LC/MS with the following conditions: Column: XBridge C18, 19×200 mm, 5-μm particles; Mobile Phase A: 5:95 acetonitrile:water with 10-mM ammonium acetate; Mobile Phase B: 95:5 acetonitrile:water with 10 mM ammonium acetate; Gradient: 4-50% B over 25 minutes, then a 5-minute hold at 100% B; Flow: 20 mL/min. Fractions containing the product were combined and dried via centrifugal evaporation. The material was further purified via preparative LC/MS with the following conditions: Column: XBridge C18, 19×200 mm, 5-μm particles; Mobile Phase A: 5:95 acetonitrile:water with 0.1% trifluoroacetic acid; Mobile Phase B: 95:5 acetonitrile:water with 0.1% trifluoroacetic acid; Gradient: 0-30% B over 19 minutes, then a 5-minute hold at 100% B; Flow: 20 mL/min. Fractions containing the desired product were combined and dried via centrifugal evaporation.

Ex 116: First eluting isomer (TFA salt) LCMS retention time 0.94 [QC-ACN-TFA-XB]. MS (ES⁺) m/z: 414.4 (M+H). ¹H NMR (500 MHz, DMSO-d₆) δ 11.00 (br s, 1H), 9.21 (s, 1H), 8.56 (br d, J=3.9 Hz, 2H), 8.42 (s, 1H), 7.65 (s, 1H), 7.31 (d, J=8.5 Hz, 1H), 7.16 (br s, 1H), 4.02 (br s, 2H), 3.24-3.12 (m, 1H), 2.98-2.89 (m, 1H), 2.56 (s, 3H), 2.46-2.35 (m, 2H), 2.25-2.10 (m, 2H), 2.06 (s, 3H), 1.90 (br s, 2H), 1.79 (br d, J=9.5 Hz, 2H), 1.31 (br s, 6H).

Ex 117: Second eluting isomer (TFA salt) LCMS retention time 1.01 [QC-ACN-TFA-XB]. MS (ES⁺) m/z: 414.4 (M+H). ¹H NMR (500 MHz, DMSO-d₆) δ 10.97 (br s, 1H), 9.21 (s, 1H), 8.72 (br s, 1H), 8.64 (br s, 1H), 8.40 (s, 1H), 7.63 (s, 1H), 7.27 (br d, J=8.2 Hz, 1H), 7.10-7.00 (m, 1H), 4.06 (br s, 2H), 3.16 (s, 1H), 2.90 (br d, J=6.8 Hz, 1H), 2.56 (s, 3H), 2.12-1.96 (m, 9H), 1.84 (br d, J=12.9 Hz, 2H), 1.31 (br s, 6H).

The examples in Table 7 were prepared starting from 6-(5-(8-azabicyclo[3.2.1] octan-3-yl)-3-isopropyl-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine, HCl, (mixture of isomers) using one of the General Methods listed above.

TABLE 7 General Ex. Method LCMS Rt HPLC No. Structure Used [M + H] (min) Method 118

A 499.2 1.08 QC- ACN- TFA-XB 119

A 499 1.41 QC- ACN- AA-XB 120

B 498.3 1.23 QC- ACN- AA-XB 121

B 498.2 1.59 QC- ACN- AA-XB 122

B 470.4 0.96 QC- ACN- TFA-XB 123

B 470.1 1.25 QC- ACN- AA-XB

BIOLOGICAL ASSAYS

The pharmacological properties of the compounds of this invention may be confirmed by a number of biological assays. The exemplified biological assays, which follow, have been carried out with compounds of the invention.

TLR7/8/9 Inhibition Reporter Assays

HEK-Blue™-cells (Invivogen) overexpressing human TLR7, TLR8 or TLR9 receptors were used for screening inhibitors of these receptors using an inducible SEAP (secreted embryonic alkaline phosphatase) reporter gene under the control of the IFN-β minimal promoter fused to five NF-κB and AP-1-binding sites. Briefly, cells are seeded into Greiner 384 well plates (15000 cells per well for TLR7, 20,000 for TLR8 and 25,000 for TLR9) and then treated with test compounds in DMSO to yield a final dose response concentration range of 0.05 nM-50 μM. After a 30 minute compound pre-treatment at room temperature, the cells are then stimulated with a TLR7 ligand (gardiquimod at a final concentration of 7.5 μM), TLR8 ligand (R848 at a final concentration of 15.9 μM) or TLR9 ligand (ODN2006 at a final concentration of 5 nM) to activate NF-κB and AP-1 which induce the production of SEAP. After a 22 hour incubation at 37° C., 5% CO₂, SEAP levels are determined with the addition of HEK-Blue™ Detection reagent (Invivogen), a cell culture medium that allows for detection of SEAP, according to manufacturer's specifications. The percent inhibition is determined as the % reduction in the HEK-Blue signal present in wells treated with agonist plus DMSO alone compared to wells treated with a known inhibitor.

TABLE 8 TLR7/8/9 Inhibition Data Ex. TLR7 IC₅₀ TLR8 IC₅₀ TLR9 IC₅₀ No. (nM) (nM) (nM) 1 22.8 139.9 902 2 4.8 12.5 528 3 27.1 40.7 340 4 56.7 2335.9 2431 5 154.2 132.6 1242 6 5.2 18.9 486 7 156.0 1230.6 3227 8 5.2 29.6 1884 9 31.0 11.5 746 10 4.6 107.4 3120 11 6.2 74.0 563 12 1.5 6.9 1898 13 6.8 98.0 1106 14 31.8 308.5 222 15 15.0 245.2 1101 16 2.0 10.2 2519 17 44.7 31.4 2766 18 65.9 714.6 685 19 48.6 29.6 1661 20 69.6 408.3 19572 21 3.9 10.1 4669 22 136.3 17.6 50000 23 54.9 375.2 50000 24 40.8 31.9 8933 25 49.5 28.5 3325 26 117.1 27.9 12390 27 0.9 3.4 3497 28 0.4 3.4 454 29 0.7 1.1 4326 30 0.3 1.3 3113 31 3.8 12.8 727 32 11.1 2.1 3674 33 29.6 7.9 5163 34 9.1 4.6 1433 35 0.7 3.0 5844 36 1.2 4.5 919 37 0.3 6.5 1522 38 280.6 402.0 3121 39 1.9 9.5 4242 40 104.2 4.5 7886 41 25.5 3.3 2849 42 32.5 6.0 3754 43 1.8 3.2 6613 44 1.7 6.5 1754 45 3.2 8.1 2308 46 2.1 8.6 8911 47 3.8 21.9 2074 48 1.9 13.5 2568 49 1.5 31.1 957 50 1.5 57.0 1094 51 2.8 31.8 1000 52 1.5 5.8 1282 53 0.9 10.1 565 54 1.9 19.5 99 55 0.9 10.6 1105 56 0.5 7.9 196 57 5.0 13.0 1305 58 0.8 0.9 1748 59 81.7 3.1 3428 60 1.7 4.3 2897 61 0.9 4.6 2274 62 1.2 6.4 381 63 1.7 7.6 10850 64 24.7 147.2 677 65 21.8 340.9 15122 66 55.5 1029.5 18633 67 60.3 16.6 10145 68 20.7 139.5 1247 69 0.6 3.0 1038 70 83.5 10.8 1073 71 12.7 1.8 1126 72 11.8 11.7 7871 73 20.4 1.9 562 74 1.2 1.7 908 75 3.3 21.7 23797 76 105.7 13.1 16069 77 55.9 3.6 4189 78 1.3 4.6 1778 79 1.1 2.0 3529 80 2.3 5.8 4552 81 2.5 10.8 2260 82 4.9 153.0 50000 83 3.4 7.2 875 84 5.7 21.6 1113 85 2.5 6.7 1992 86 1.2 26.8 6204 87 2.4 12.8 1301 88 1.9 33.4 344 89 0.1 3.3 773 90 17.3 245.0 1503 91 1.5 4.6 1808 92 5.6 15.2 3272 93 1.6 4.0 2798 94 0.6 11.9 914 95 0.7 20.5 2075 96 1.2 35.8 376 97 2.3 56.1 768 98 1.0 12.1 1792 99 1.7 8.3 2225 100 13.7 31.6 4444 101 12.3 12.4 1440 102 3.9 8.2 5462 103 5.1 11.7 10200 104 2.5 14.6 917 105 5.9 134.2 188 106 43.0 39.1 382 107 40.7 591.2 918 108 78.7 30.4 216 110 6.3 19.4 6626 111 23.9 112.9 19234 112 20.6 120.9 7419 113 2.4 59.6 4832 114 13.7 225.5 7324 115 5.6 29.7 14574 116 9.9 101.8 1110 117 31.6 494.2 6089 118 8.7 158.5 5461 119 12.9 103.1 1016 120 6.7 45.9 3805 121 3.2 47.6 4844 122 2.3 98.9 5937 123 7.6 151.2 8477 

The invention claimed is:
 1. A compound of Formula (I)

or a salt thereof, wherein: R₁ is H, Cl, —CN, C₁₋₄ alkyl, C₁₋₃ fluoroalkyl, C₁₋₃ hydroxy-fluoroalkyl, —CR_(z)═CH₂, C₃₋₆ cycloalkyl, —CH₂(C₃₋₆ cycloalkyl), —C(O)O(C₁₋₃ alkyl), or tetrahydropyranyl; each R₂ is independently halo, —CN, —OH, —NO₂ ⁺, C₁₋₃ alkyl, C₁₋₂ fluoroalkyl, C₁₋₃ hydroxyalkyl, C₁₋₃ aminoalkyl, —(CH₂)₀₋₄O(C₁₋₃ alkyl), C₁₋₃ fluoroalkoxy, C₂₋₄ alkoxyalkoxy, —O(CH₂)₁₋₂NR_(x)R_(x), —C(O)O(C₁₋₃ alkyl), —C(O)NR_(y)R_(y), —NR_(y)R_(y), —NR_(x)C(O)(C₁₋₃ alkyl), —NR_(x)(CH₂-cyclopropyl), C₃₋₆ cycloalkyl, methylpiperidinyl, methylpiperazinyl, amino-oxadiazolyl, imidazolyl, triazolyl, or —C(O)(thiazolyl); R₃ is: (a) -L₁-A; or (b) H, C₁₋₆ alkyl, C₁₋₃ fluoroalkyl, C₁₋₃ cyanoalkyl, C₁₋₆ hydroxyalkyl, C₁₋₃ hydroxy-fluoroalkyl, —CR_(x)R_(x)CR_(x)(OH)CR_(x)═CR_(x)R_(x), —(CR_(x)R_(x))₁₋₄O(C₁₋₃ alkyl), —(CR_(x)R_(x))₁₋₄O(CR_(x)R_(x))₁₋₃O(C₁₋₃ alkyl), —CH₂CH(OH)CH₂O(C₁₋₃ alkyl), —(CR_(x)R_(x))₁₋₃S(C₁₋₃ alkyl), —(CH₂)₁₋₃ C(O)OC(CH₃)₃, —(CR_(x)R_(x))₀₋₃NR_(x)R_(y), —(CR_(x)R_(x))₀₋₃NR_(x)(C₁₋₄ hydroxyalkyl), —CH₂CH(OH)CH₂NR_(x)R_(y), —C(O)H, C(O)(C₁₋₆ alkyl), —C(O)(C₁₋₃ hydroxyalkyl), —C(O)(C₁₋₃ fluoroalkyl), —C(O)(C₁₋₃ chloroalkyl), —C(O)(C₁₋₃ cyanoalkyl), —(CR_(x)R_(x))₀₋₃C(O)OH, —C(O)(CH₂)₀₋₂O(C₁₋₄ alkyl), —C(O)(CR_(x)R_(x))₀₋₂O(CR_(x)R_(x))₁₋₂O(C₁₋₃ alkyl), —C(O)CR_(x)R_(x)S(O)₂(C₁₋₃ alkyl), —C(O)CR_(x)R_(x)NR_(x)S(O)₂(C₁₋₃ alkyl), —C(O)CR_(x)R_(x)OC(O)(C₁₋₃ alkyl), —C(O)(CR_(x)R_(x))₀₋₃NR_(y)R_(y), —C(O)(CR_(x)R_(x))₀₋₁NR_(x)(C₁₋₃ cyanoalkyl), —C(O)(CR_(x)R_(x))₀₋₂NR_(y)(C₁₋₆ hydroxyalkyl), —C(O)(CR_(x)R_(x))₀₋₁NR_(x)(C₁₋₃ fluoroalkyl), —C(O)(CR_(x)R_(x))₀₋₁NR_(x)(C₁₋₅ hydroxy-fluoroalkyl), —C(O)(CR_(x)R_(x))₀₋₁NR_(x)(CH₂)₁₋₂O(C₁₋₃ hydroxyalkyl), —C(O)(CR_(x)R_(x))₀₋₁NR_(x)(CH₂)₁₋₂NR_(x)C(O)(C₁₋₂ alkyl), —C(O)(CR_(x)R_(x))₀₋₁NR_(x)(CR_(x)R_(x))₁₋₂O(C₁₋₂ alkyl)), —C(O)CR_(x)(NH₂)(CR_(x)R_(x))₁₋₄NR_(x)R_(x), —C(O)CR_(x)(NH₂)(CR_(x)R_(x))₁₋₄NR_(x)C(O)NR_(x)R_(x), —C(O)(CR_(x)R_(x))₀₋₃NR_(x)(CH₂)₀₋₁C(O)(C₁₋₃ alkyl), —C(O)(CR_(x)R_(x))₀₋₁NR_(x)(CH₂)₀₋₁C(O)(C₁₋₃ cyanoalkyl), —C(O)(CR_(x)R_(x))₀₋₁NR_(x)(CH₂)₁₋₂C(O)NR_(y)R_(y), —C(O)(CR_(x)R_(x))₁₋₃C(O)NR_(y)R_(y), —C(O)(CR_(x)R_(x))₀₋₁NR_(x)(CHR_(y)(CH₂OH)), —(CR_(x)R_(x))₁₋₂C(O)NR_(y)R_(y), —(CR_(x)R_(x))₁₋₂C(O)NR_(y)(C₁₋₃ fluoroalkyl), —(CR_(x)R_(x))₁₋₂C(O)NR_(y)(C₁₋₄ hydroxyalkyl), —(CR_(x)R_(x))₁₋₂C(O)NR_(y)(C₁₋₃ cyanoalkyl), —(CR_(x)R_(x))₁₋₂C(O)NR_(x)(CH₂)₁₋₂O(C₁₋₃ alkyl), —(CR_(x)R_(x))₁₋₂C(O)NR_(x)CH(C₁₋₄ alkyl)(C₁₋₃ hydroxyalkyl), —(CH₂)₁₋₂C(O)NR_(x)(CH₂)₁₋₂C(O)NR_(x)R_(x), —(CH₂)₁₋₂C(O)NR_(x)(CH₂)₁₋₂S(O)₂OH, —(CH₂)₁₋₂C(O)NR_(x)(CH₂)₁₋₂NR_(x)C(O)(C₁₋₃ alkyl), —(CH₂)₁₋₂C(O)NR_(x)(CH₂)₁₋₃NR_(x)R_(x), —(CH₂)₁₋₂C(O)N(CH₂CH₃)(CH₂)₁₋₃NR_(x)R_(x), —(CH₂)₀₋₂S(O)₂(C₁₋₄ alkyl), —(CH₂)₀₋₂S(O)₂(C₁₋₃ fluoroalkyl), —(CH₂)₀₋₂S(O)₂NR_(x)R_(x), —C(O)C(O)OH, —C(O)C(O)NR_(y)R_(y), or —C(O)C(O)NR_(y)(CR_(x)R_(x))₁₋₂NR_(y)R_(y); L₁ is a bond, —(CR_(x)R_(x))₁₋₂—, —(CR_(x)R_(x))₁₋₂CR_(x)(OH)—, —(CR_(x)R_(x))₁₋₂O—, —CR_(x)R_(x)C(O)—, —(CR_(x)R_(x))₂NR_(x)(CR_(x)R_(x))₀₋₁—, —CR_(x)R_(x)C(O)NR_(x)(CR_(x)R_(x))₀₋₄—, —C(O)(CR_(x)R_(x))₀₋₃—, —C(O)(CR_(x)R_(x))₀₋₂NR_(x)(CR_(x)R_(x))₀₋₂—, —C(O)(CR_(x)R_(x))₀₋₂N(C₁₋₂ hydroxyalkyl)(CR_(x)R_(x))₀₋₂—, —C(O)(CR_(x)R_(x))₀₋₂NR_(x)(CR_(x)R_(x))₁₋₂CR_(x)(OH)—, —C(O)(CR_(x)R_(x))₁₋₂C(O)NR_(x)—, —(CR_(x)R_(x))₀₋₂C(O)NR_(x)(CR_(x)R_(x))₁₋₂CR_(x)(OH)—, —(CR_(x)R_(x))₀₋₂C(O)N(C₁₋₂ hydroxyalkyl)(CR_(x)R_(x))₁₋₂—, —C(O)(CR_(x)R_(x))₀₋₁O—, —C(O)(CR_(x)R_(x))₁₋₂NHS(O)₂—, —C(O)CR_(x)(NH₂)CR_(x)R_(x)—, —C(O)C(O)(CR_(x)R_(x))₀₋₂—, —C(O)NR_(x)(CR_(x)R_(x))₁₋₂—, or —S(O)₂—; A is 2-oxa-6-azaspiro[3,3]heptanyl, 4-oxaspiro[2.5]octanyl, 7-azaspiro[3.5]nonanyl, 8-azabicyclo[3.2.1]octanyl, 8-oxa-3-azabicyclo[3.2.1]octanyl, 9-azabicyclo[3.3.1]nonanyl, adamantanyl, azepanyl, azetidinyl, C₃₋₆ cycloalkyl, diazepanyl, dihydroinonyl, dihydropyrimidinonyl, dioxidoisothiazolidinyl, dioxidothiazinanyl, dioxotetrahydrothiophenyl, dioxotetrahydrothiopyranyl, dioxothiomorpholinyl, furanyl, imidazolyl, imidazolidinonyl, indolyl, isoquinolinyl, isoxazolyl, morpholinyl, morpholinonyl, naphthalenyl, octahydrocyclopenta[b]pyranyl, oxazolidinonyl, oxadiazolyl, oxetanyl, oxazolyl, phenyl, piperidinyl, piperidinonyl, piperazinyl, piperazinonyl, pyrazinyl, pyrazolyl, pyridazinonyl, pyridinonyl, pyridinyl, pyrimidinyl, pyrrolidinonyl, pyrrolidinyl, pyrrolyl, quinolinyl, quinolizinonyl, tetrahydrofuranyl, tetrahydropyranyl, tetrazolyl, thiadiazolyl, thiazolyl, or triazolyl, each substituted with -L₂-R_(a) and zero to 4 R_(b); L₂ is a bond or —CR_(x)R_(x)—; R_(a) is: (a) H, F, Cl, —CN, —OH, C₁₋₆ alkyl, C₁₋₃ fluoroalkyl, C₁₋₅ hydroxyalkyl, —(CH₂)₀₋₄O(C₁₋₃ alkyl), —(CR_(x)R_(x))₁₋₃S(C₁₋₃ alkyl), —(CR_(x)R_(x))₁₋₃NHC(O)O(C₁₋₄ alkyl), —(CR_(x)R_(x))₁₋₃NR_(y)R_(y), —(CR_(x)R_(x))₁₋₃C(O)NR_(y)R_(y), —O(C₁₋₃ fluoroalkyl), —S(O)₂NR_(x)R_(x), —O(CR_(x)R_(x))₁₋₃NR_(x)R_(x), —NHS(O)₂(C₁₋₃ alkyl), —NR_(x)R_(x), —NR_(x)(C₁₋₄ alkyl), —NR_(x)C(O)(C₁₋₄ alkyl), —(CR_(x)R_(x))₀₋₃C(O)OH, —C(O)(C₁₋₅ alkyl), —C(O)(C₁₋₃ fluoroalkyl), —C(O)O(C₁₋₄ alkyl), —C(O)NH(C₁₋₃ cyanoalkyl), —C(O)NR_(y)R_(y), —C(O)NR_(x)CH₂C(O)NR_(x)R_(x), or —C(O)NR_(x)CH₂CH₂NHC(O)(C₁₋₃ alkyl); (b) C₃₋₆ cycloalkyl or —C(O)NH(C₃₋₆ cycloalkyl), wherein each cycloalkyl is substituted with zero to 2 substituents independently selected from —OH, C₁₋₃ alkyl, C₁₋₃ hydroxyalkyl, C₁₋₃ fluoroalkyl, and —C(O)O(C₁₋₃ alkyl); or (c) A₁, —CH₂A₁, —C(O)A₁, —NR_(x)A₁, or —C(O)NR_(x)A₁, wherein A₁ is furanyl, imidazolyl, indolyl, isoxazolyl, morpholinyl, octahydropyrrolo[3,4-c]pyrrolyl, oxazolyl, oxetanyl, phenyl, piperazinyl, piperidinyl, pyrazolyl, pyridinyl, pyrimidinyl, pyrrolidinyl, pyrrolyl, tetrahydrofuranyl, tetrahydropyranyl, thiadiazolyl, thiazolyl, thiophenyl, or triazolyl, each substituted with zero to three substituents independently selected from —OH, C₁₋₃ alkyl, C₁₋₃ hydroxyalkyl, —C(O)(C₁₋₂ alkyl), —C(O)O(C₁₋₃ alkyl), —NR_(x)R_(x), phenyl, trifluoromethyl-phenyl, —CH₂(bromophenyl), and —CH₂CH₂(pyrrolidinyl); each R_(b) is independently F, —CH₃, —CF₃, or —OCH₃; each R_(x) is independently H or —CH₃; each R_(y) is independently H or C₁₋₆ alkyl; R_(z) is H, C₁₋₂ alkyl, or C₁₋₂ fluoroalkyl; R_(4a), R_(4b), R_(4c), and R_(4c) are independently H, F, —OH, C₁₋₂ alkyl, or —OCH₃; or R_(4a) and R_(4c) join together to form —CH₂CH₂—; R₅ is F, Cl, —CN, C₁₋₂ alkyl, C₁₋₂ fluoroalkyl, or —OCH₃; m is zero, 1, 2, 3, or 4; n is zero, 1, or 2; and p is zero, 1, 2, 3, or
 4. 2. The compound according to claim 1 or a salt thereof, wherein: R₁ is H, Cl, —CN, C₁₋₄ alkyl, or C₁₋₂ fluoroalkyl; each R₂ is independently F, Cl, —CN, —OH, C₁₋₃ alkyl, —OCH₃, —CH₂OH, —CH₂OCH₃, or —CH₂CH₂OCH₃; R₃ is (a) -L₁-A; or (b) H, C₁₋₄ alkyl, C₁₋₄ fluoroalkyl, C₁₋₄ hydroxyalkyl, C₁₋₃ cyanoalkyl, —(CR_(x)R_(x))₁₋₄O(C₁₋₃ alkyl), —(CH₂)₁₋₂S(O)₂(C₁₋₄ alkyl), —(CR_(x)R_(x))₁₋₂C(O)NR_(y)R_(y), or —C(O)(CR_(x)R_(x))₀₋₃NR_(y)R_(y); L₁ is a bond or —(CR_(x)R_(x))₁₋₂—; A is a ring selected from C₃₋₆ cycloalkyl, oxetanyl, tetrahydrofuranyl, tetrahydropyranyl, pyrazolyl, triazolyl, pyrimidinyl, oxazolidinonyl, pyrrolidinonyl, or dioxo-isothiazolidinyl, each substituted with R_(a) and zero to 4 R_(b); R_(a) is H, —CN, —OH, C₁₋₃ alkyl, C₁₋₂ fluoroalkyl, C₁₋₃ hydroxyalkyl, or —(CH₂)₁₋₂O(C₁₋₃ alkyl); each R_(b) is independently F, —CH₃, or —OCH₃; R_(4a), R_(4b), R_(4c), and R_(4d) are independently H or —CH₃; or R_(4a) and R_(4c) join together to form —CH₂CH₂—; and n is zero or 1; and p is zero, 1, or
 2. 3. The compound according to claim 1 or a salt thereof, wherein: R₁ is —CH(CH₃)₂; each R₂ is independently Cl, —CH₃, —OCH₃, or —CH₂OCH₃; R₃ is H, —CH₃, —CH(CH₃)₂, —CH₂CN, —CH₂CH₂OH, —CH₂CH₂OCH₃, —CH₂CH₂S(O)₂CH₃, —CH₂CH₂CH₂CF₃, —CH₂C(CH₃)₂OH, —CH₂C(O)NH(CH₃), —CH₂C(O)N(CH₃)₂, —C(O)CH₂N(CH₃)₂, difluorocyclohexyl, oxetanyl, tetrahydrofuranyl, tetrahydropyranyl, —CH₂(oxetanyl), —CH₂(methyloxetanyl), —CH₂(methylpyrazolyl), —CH₂(methyltriazolyl), —CH₂(methylpyrimidinyl), —CH₂(methoxypyrimidinyl), —CH₂CH₂(oxazolidinonyl), —CH₂CH₂(pyrrolidinonyl), or —CH₂CH₂(dioxo-isothiazolidinyl); R_(4a), R_(4b), R_(4c), and R_(4d) are independently H or —CH₃; or R_(4a) and R_(4c) join together to form —CH₂CH₂—; and n is zero; and p is zero, 1, or
 2. 4. The compound according to claim 1 or a salt thereof, wherein R_(4a), R_(4b), R_(4c), and R_(4d) are independently H or —CH₃.
 5. The compound according to claim 1 or a salt thereof, wherein R_(4a) and R_(4c) join together to form —CH₂CH₂—; R_(4b) is H; and R_(4d) is H.
 6. A pharmaceutical composition comprising a compound according claim 1 or a pharmaceutically-acceptable salt thereof; and a pharmaceutically acceptable carrier.
 7. The compound according to claim 1 or a salt thereof, wherein: R₃ is -L₁-A.
 8. The compound according to claim 1 or a salt thereof, wherein: R₃ is -L₁-A; and L₁ is a bond.
 9. The compound according to claim 1 or a salt thereof, wherein: R₃ is —L₁—A; and L₁ is —(CR_(x)R_(x))₁₋₂—.
 10. The compound according to claim 1 or a salt thereof, wherein: R₃ is H, C₁₋₄ alkyl, C₁₋₄ fluoroalkyl, C₁₋₄ hydroxyalkyl, C₁₋₃ cyanoalkyl, —(CR_(x)R_(x))₁₋₄O(C₁₋₃ alkyl), —(CH₂)₁₋₂S(O)₂(C₁₋₄ alkyl), —(CR_(x)R_(x))₁₋₂C(O)NR_(y)R_(y), or —C(O)(CR_(x)R_(x))₀₋₃NR_(y)R_(y).
 11. The compound according to claim 1 or a salt thereof, wherein said compound is selected from: 6-(3-isopropyl-5-(piperidin-4-yl)-1H-indol-2-yl)-[1,2,4]triazolo[4,3-a] pyridine (1); 6-(3-isopropyl-5-(piperidin-4-yl)-1H-indol-2-yl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridine (2); 6-(3-isopropyl-5-(piperidin-4-yl)-1H-indol-2-yl)-3-methyl-[1,2,4] triazolo[4,3-a]pyridine (3); 6-(3-isopropyl-5-(piperidin-4-yl)-1H-indol-2-yl)-7-methyl-[1,2,4]triazolo[4,3-a]pyridine (4); 6-(3-isopropyl-5-(piperidin-4-yl)-1H-indol-2-yl)-5-methyl-[1,2,4]triazolo[4,3-a]pyridine (5); 6-(3-isopropyl-5-(piperidin-4-yl)-1H-indol-2-yl)-3,8-dimethyl-[1,2,4]triazolo[4,3-a] pyridine (6); 6-(3-isopropyl-5-(piperidin-4-yl)-1H-indol-2-yl)-3-(methoxymethyl)-[1,2,4]triazolo[4,3-a]pyridine (7); 6-(3-isopropyl-5-(piperidin-4-yl)-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a] pyridine (8); 6-(3-isopropyl-5-(piperidin-4-yl)-1H-indol-2-yl)-5,8-dimethyl-[1,2,4]triazolo[4,3-a] pyridine (9); 8-chloro-6-(3-isopropyl-5-(piperidin-4-yl)-1H-indol-2-yl)-7-methyl-[1,2,4]triazolo[4,3-a] pyridine (10); 6-(3-isopropyl-5-(piperidin-4-yl)-1H-indol-2-yl)-8-methoxy-[1,2,4] triazolo[4,3-a] pyridine (11); 2-(4-(3-isopropyl-2-(8-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1H-indol-5-yl) piperidin-1-yl)-N,N-dimethylacetamide (12); 2-(4-(2-([1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-isopropyl-1H-indol-5-yl)piperidin-1-yl)-N-methylacetamide (13); 2-(4-(2-([1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-isopropyl-1H-indol-5-yl)piperidin-1-yl)-N,N-dimethylacetamide (14); 2-(4-(3-isopropyl-2-(7-methyl-[1,2,4]triazolo[4,3-a] pyridin-6-yl)-1H-indol-5-yl) piperidin-1-yl)-N-methylacetamide (15); 2-(4-(3-isopropyl-2-(8-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1H-indol-5-yl) piperidin-1-yl)-N-methylacetamide (16); 2-(4-(3-isopropyl-2-(3-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1H-indol-5-yl) piperidin-1-yl)-N-methylacetamide (17); 2-(4-(3-isopropyl-2-(7-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1H-indol-5-yl) piperidin-1-yl)-N,N-dimethylacetamide (18); 2-(4-(3-isopropyl-2-(3-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1H-indol-5-yl) piperidin-1-yl)-N,N-dimethylacetamide (19); 6-(3-isopropyl-5-(1-((1-methyl-1H-1,2,4-triazol-3-yl)methyl)piperidin-4-yl)-1H-indol-2-yl)-7-methyl-[1,2,4]triazolo[4,3-a] pyridine (20); 6-(3-isopropyl-5-(1-((1-methyl-1H-1,2,4-triazol-3-yl)methyl)piperidin-4-yl)-1H-indol-2-yl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridine (21); 6-(3-isopropyl-5-(1-((1-methyl-1H-1,2,4-triazol-3-yl)methyl)piperidin-4-yl)-1H-indol-2-yl)-3-methyl-[1,2,4] triazolo[4,3-a]pyridine (22); 6-(3-isopropyl-5-(1-((1-methyl-1H-1,2,4-triazol-3-yl)methyl)piperidin-4-yl)-1H-indol-2-yl)-[1,2,4]triazolo[4,3-a]pyridine (23); 2-(4-(3-isopropyl-2-(5-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1H-indol-5-yl) piperidin-1-yl)-N-methylacetamide (24); 2-(4-(3-isopropyl-2-(5-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1H-indol-5-yl) piperidin-1-yl)-N,N-dimethylacetamide (25); 6-(3-isopropyl-5-(1-((1-methyl-1H-1,2,4-triazol-3-yl)methyl)piperidin-4-yl)-1H-indol-2-yl)-5-methyl-[1,2,4] triazolo[4,3-a]pyridine (26); 6-(3-isopropyl-5-(1-(2-methoxyethyl)piperidin-4-yl)-1H-indol-2-yl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridine (27); 2-(4-(3-isopropyl-2-(8-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1H-indol-5-yl) piperidin-1-yl)ethan-1-ol (28); 6-(3-isopropyl-5-(1-((3-methyloxetan-3-yl)methyl)piperidin-4-yl)-1H-indol-2-yl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridine (29); 6-(3-isopropyl-5-(1-(oxetan-3-ylmethyl)piperidin-4-yl)-1H-indol-2-yl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridine (30); 2-(4-(2-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-isopropyl-1H-indol-5-yl) piperidin-1-yl)acetonitrile (31); 6-(3-isopropyl-5-(1-(2-(methylsulfonyl)ethyl)piperidin-4-yl)-1H-indol-2-yl)-3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (32); 6-(3-isopropyl-5-(1-((1-methyl-1H-1,2,4-triazol-3-yl)methyl)piperidin-4-yl)-1H-indol-2-yl)-3,8-dimethyl-[1,2,4]triazolo[4,3-a] pyridine (33); 2-(4-(2-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-isopropyl-1H-indol-5-yl) piperidin-1-yl)-N,N-dimethylacetamide (34); 6-(3-isopropyl-5-(1-(2-(methylsulfonyl)ethyl)piperidin-4-yl)-1H-indol-2-yl)-8-methyl-[1,2,4]triazolo[4,3-a] pyridine (35); 6-(3-isopropyl-5-(1-(4,4,4-trifluorobutyl)piperidin-4-yl)-1H-indol-2-yl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridine (36); 2-(4-(3-isopropyl-2-(8-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1H-indol-5-yl) piperidin-1-yl)acetonitrile (37); 2-(4-(3-isopropyl-2-(3-(methoxymethyl)-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1H-indol-5-yl)piperidin-1-yl)-N,N-dimethylacetamide (38); 2-(4-(2-(7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-isopropyl-1H-indol-5-yl) piperidin-1-yl)-N,N-dimethylacetamide (39); 6-(3-isopropyl-5-(1-((1-methyl-1H-1,2,4-triazol-3-yl)methyl)piperidin-4-yl)-1H-indol-2-yl)-5,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (40); 6-(3-isopropyl-5-(1-(4,4,4-trifluorobutyl)piperidin-4-yl)-1H-indol-2-yl)-5,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (41); 2-(4-(2-(5,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-isopropyl-1H-indol-5-yl) piperidin-1-yl)-N,N-dimethylacetamide (42); 6-(3-isopropyl-5-(1-(2-(methylsulfonyl)ethyl)piperidin-4-yl)-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (43); 6-(3-isopropyl-5-(1-(4,4,4-trifluorobutyl)piperidin-4-yl)-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a] pyridine (44); 6-(3-isopropyl-5-(1-((1-methyl-1H-1,2,4-triazol-3-yl)methyl)piperidin-4-yl)-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (45); 8-chloro-6-(3-isopropyl-5-(1-(2-(methylsulfonyl)ethyl)piperidin-4-yl)-1H-indol-2-yl)-7-methyl-[1,2,4] triazolo[4,3-a]pyridine (46); 8-chloro-6-(3-isopropyl-5-(1-((1-methyl-1H-1,2,4-triazol-3-yl)methyl)piperidin-4-yl)-1H-indol-2-yl)-7-methyl-[1,2,4]triazolo[4,3-a]pyridine (47); 8-chloro-6-(3-isopropyl-5-(1-(4,4,4-trifluorobutyl)piperidin-4-yl)-1H-indol-2-yl)-7-methyl-[1,2,4]triazolo[4,3-a]pyridine (48); 2-(4-(2-(8-chloro-7-methyl-[1,2,4]triazolo[4,3-a] pyridin-6-yl)-3-isopropyl-1H-indol-5-yl)piperidin-1-yl)-N,N-dimethylacetamide (49); 2-(4-(2-(8-chloro-7-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-isopropyl-1H-indol-5-yl) piperidin-1-yl)acetonitrile (50); 2-(4-(2-(7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-isopropyl-1H-indol-5-yl) piperidin-1-yl)acetonitrile (51); 2-(2-(4-(2-(7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-isopropyl-1H-indol-5-yl) piperidin-1-yl)ethyl)isothiazolidine 1,1-dioxide (52); 2-(2-(4-(2-(8-chloro-7-methyl-[1,2,4]triazolo[4,3-a] pyridin-6-yl)-3-isopropyl-1H-indol-5-yl)piperidin-1-yl)ethyl)isothiazolidine 1,1-dioxide (53); 2-(4-(3-isopropyl-2-(8-methoxy-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1H-indol-5-yl) piperidin-1-yl)-N,N-dimethylacetamide (54); 6-(3-isopropyl-5-(1-(4,4,4-trifluorobutyl)piperidin-4-yl)-1H-indol-2-yl)-8-methoxy-[1,2,4]triazolo[4,3-a]pyridine (55); 3-(2-(4-(2-(7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-isopropyl-1H-indol-5-yl) piperidin-1-yl)ethyl)oxazolidin-2-one (56); 1-(2-(4-(2-(7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-isopropyl-1H-indol-5-yl) piperidin-1-yl)ethyl)pyrrolidin-2-one (57); 1-(4-(3-isopropyl-2-(8-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1H-indol-5-yl) piperidin-1-yl)-2-methylpropan-2-ol (58); 1-(4-(2-(5,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-isopropyl-1H-indol-5-yl) piperidin-1-yl)-2-methylpropan-2-ol (59); 1-(4-(2-(7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-isopropyl-1H-indol-5-yl) piperidin-1-yl)-2-methylpropan-2-ol (60); 1-(4-(2-(8-chloro-7-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-isopropyl-1H-indol-5-yl) piperidin-1-yl)-2-methylpropan-2-ol (61); 1-(4-(3-isopropyl-2-(8-methoxy-5-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1H-indol-5-yl)piperidin-1-yl)-2-methylpropan-2-ol (62); 6-(3-isopropyl-5-(1-(oxetan-3-yl)piperidin-4-yl)-1H-indol-2-yl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridine (63); 6-(3-isopropyl-5-(1-(tetrahydro-2H-pyran-4-yl)piperidin-4-yl)-1H-indol-2-yl)-[1,2,4]triazolo[4,3-a]pyridine (64); 6-(3-isopropyl-5-(1-(oxetan-3-yl)piperidin-4-yl)-1H-indol-2-yl)-[1,2,4]triazolo[4,3-a] pyridine (65); 6-(3-isopropyl-5-(1-(oxetan-3-yl)piperidin-4-yl)-1H-indol-2-yl)-7-methyl-[1,2,4]triazolo[4,3-a]pyridine (66); 6-(3-isopropyl-5-(1-(oxetan-3-yl)piperidin-4-yl)-1H-indol-2-yl)-3-methyl-[1,2,4]triazolo[4,3-a]pyridine (67); 6-(3-isopropyl-5-(1-(tetrahydro-2H-pyran-4-yl)piperidin-4-yl)-1H-indol-2-yl)-7-methyl-[1,2,4]triazolo[4,3-a]pyridine (68); 6-(3-isopropyl-5-(1-(tetrahydro-2H-pyran-4-yl)piperidin-4-yl)-1H-indol-2-yl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridine (69); 6-(3-isopropyl-5-(1-(tetrahydro-2H-pyran-4-yl)piperidin-4-yl)-1H-indol-2-yl)-5-methyl-[1,2,4]triazolo[4,3-a]pyridine (70); 6-(3-isopropyl-5-(1-((1-methyl-1H-pyrazol-3-yl)methyl)piperidin-4-yl)-1H-indol-2-yl)-3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (71); 6-(3-isopropyl-5-(1-(oxetan-3-yl)piperidin-4-yl)-1H-indol-2-yl)-3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (72); 6-(3-isopropyl-5-(1-(tetrahydro-2H-pyran-4-yl)piperidin-4-yl)-1H-indol-2-yl)-3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (73); 6-(3-isopropyl-5-(1-((1-methyl-1H-pyrazol-3-yl)methyl)piperidin-4-yl)-1H-indol-2-yl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridine (74); 6-(3-isopropyl-5-(1-(oxetan-3-yl)piperidin-4-yl)-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (75); 6-(3-isopropyl-5-(1-(oxetan-3-yl)piperidin-4-yl)-1H-indol-2-yl)-5,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (76); 6-(3-isopropyl-5-(1-(tetrahydro-2H-pyran-4-yl)piperidin-4-yl)-1H-indol-2-yl)-5,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (77); 6-(3-isopropyl-5-(1-(tetrahydro-2H-pyran-4-yl)piperidin-4-yl)-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (78); 6-(3-isopropyl-5-(1-((3-methyloxetan-3-yl)methyl)piperidin-4-yl)-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (79); 8-chloro-6-(3-isopropyl-5-(1-((3-methyloxetan-3-yl)methyl)piperidin-4-yl)-1H-indol-2-yl)-7-methyl-[1,2,4]triazolo[4,3-a]pyridine (80); 8-chloro-6-(3-isopropyl-5-(1-(tetrahydro-2H-pyran-4-yl)piperidin-4-yl)-1H-indol-2-yl)-7-methyl-[1,2,4]triazolo[4,3-a]pyridine (81); 8-chloro-6-(3-isopropyl-5-(1-(oxetan-3-yl)piperidin-4-yl)-1H-indol-2-yl)-7-methyl-[1,2,4] triazolo[4,3-a]pyridine (82); 6-(3-isopropyl-5-(1-((1-methyl-1H-1,2,3-triazol-4-yl)methyl)piperidin-4-yl)-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (83); 8-chloro-6-(3-isopropyl-5-(1-((1-methyl-1H-1,2,3-triazol-4-yl)methyl)piperidin-4-yl)-1H-indol-2-yl)-7-methyl-[1,2,4]triazolo[4,3-a]pyridine (84); 6-(5-(1-(2,2-dimethyltetrahydro-2H-pyran-4-yl)piperidin-4-yl)-3-isopropyl-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (85); 6-(3-isopropyl-5-(1-(oxetan-3-yl)piperidin-4-yl)-1H-indol-2-yl)-8-methoxy-[1,2,4]triazolo[4,3-a]pyridine (86); 6-(5-(1-(2,6-dimethyltetrahydro-2H-pyran-4-yl)piperidin-4-yl)-3-isopropyl-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (87); 6-(3-isopropyl-5-(1-(tetrahydro-2H-pyran-4-yl)piperidin-4-yl)-1H-indol-2-yl)-8-methoxy-[1,2,4]triazolo[4,3-a]pyridine (88); 6-(3-isopropyl-5-(1-((2-methoxypyrimidin-5-yl)methyl)piperidin-4-yl)-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (89); 6-(3-isopropyl-5-(1-((3-methyloxetan-3-yl)methyl)piperidin-4-yl)-1H-indol-2-yl)-8-methoxy-[1,2,4]triazolo[4,3-a]pyridine (90); 6-(3-isopropyl-5-(1-((2-methylpyrimidin-5-yl)methyl)piperidin-4-yl)-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (91); 6-(5-(1-(2,6-dimethyltetrahydro-2H-pyran-4-yl)piperidin-4-yl)-3-isopropyl-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a] pyridine (92); 6-(3-isopropyl-5-(1-(tetrahydrofuran-3-yl)piperidin-4-yl)-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (93); 6-(3-isopropyl-5-(1-(tetrahydrofuran-3-yl)piperidin-4-yl)-1H-indol-2-yl)-8-methoxy-[1,2,4]triazolo[4,3-a]pyridine (94); 6-(5-(1-(4,4-difluorocyclohexyl)piperidin-4-yl)-3-isopropyl-1H-indol-2-yl)-8-methoxy-[1,2,4] triazolo[4,3-a]pyridine (95); 6-(3-isopropyl-5-(1-methylpiperidin-4-yl)-1H-indol-2-yl)-8-methoxy-[1,2,4]triazolo[4,3-a]pyridine (96); 6-(3-isopropyl-5-(1-isopropylpiperidin-4-yl)-1H-indol-2-yl)-8-methoxy-[1,2,4]triazolo[4,3-a]pyridine (97); 6-(3-isopropyl-5-(1-methylpiperidin-4-yl)-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (98); 6-(3-isopropyl-5-(1-isopropylpiperidin-4-yl)-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo [4,3-a]pyridine (99); 6-(3-isopropyl-5-(1-(2,2,6,6-tetramethyltetrahydro-2H-pyran-4-yl)piperidin-4-yl)-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (100); 6-(5-(1-(4,4-difluorocyclohexyl)piperidin-4-yl)-3-isopropyl-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (101); 6-(3-isopropyl-5-(1-(tetrahydrofuran-3-yl)piperidin-4-yl)-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (102 and 103); 2-(dimethylamino)-1-(4-(3-isopropyl-2-(8-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1H-indol-5-yl)piperidin-1-yl)ethanone (104); 1-(4-(2-([1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-isopropyl-1H-indol-5-yl)piperidin-1-yl)-2-(dimethylamino)ethan-1-one (105); 2-(dimethylamino)-1-(4-(3-isopropyl-2-(3-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1H-indol-5-yl)piperidin-1-yl)ethan-1-one (106); 2-(dimethylamino)-1-(4-(3-isopropyl-2-(7-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1H-indol-5-yl)piperidin-1-yl)ethan-1-one (107); 2-(dimethylamino)-1-(4-(3-isopropyl-2-(5-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1H-indol-5-yl)piperidin-1-yl)ethan-1-one (108); 6-(5-(2,6-dimethylpiperidin-4-yl)-3-isopropyl-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (109); 6-(5-(2,6-dimethyl-1-(2-(methylsulfonyl)ethyl)piperidin-4-yl)-3-isopropyl-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (110 to 111); 2-(4-(2-(7,8-dimethyl-[1,2,4] triazolo[4,3-a]pyridin-6-yl)-3-isopropyl-1H-indol-5-yl)-2,6-dimethylpiperidin-1-yl)-N,N-dimethylacetamide (112); 6-(5-(2,6-dimethyl-1-((3-methyloxetan-3-yl)methyl)piperidin-4-yl)-3-isopropyl-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (113 to 114); and 6-(5-(2,6-dimethyl-1-(oxetan-3-yl)piperidin-4-yl)-3-isopropyl-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (115).
 12. The compound according to claim 1 or a salt thereof, wherein said compound is selected from: 6-(5-(8-azabicyclo[3.2.1]octan-3-yl)-3-isopropyl-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (116 and 117); 2-((1R,5S)-3-(2-(7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-isopropyl-1H-indol-5-yl)-8-azabicyclo[3.2.1]octan-8-yl)-N,N-dimethylacetamide (118 and 119); 6-(3-isopropyl-5-((1R,5S)-8-((3-methyloxetan-3-yl)methyl)-8-azabicyclo[3.2.1]octan-3-yl)-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine (120 and 121); and 6-(3-isopropyl-5-((1R,5S)-8-(oxetan-3-yl)-8-azabicyclo[3.2.1]octan-3-yl)-1H-indol-2-yl)-7,8-dimethyl-[1,2,4]triazolo[4,3-a] pyridine (122 and 123).
 13. A method of treating an autoimmune disease or a chronic inflammatory disease, comprising administering to a mammalian patent a compound according to claim 1 or a pharmaceutically acceptable salt thereof, wherein said autoimmune disease or chronic inflammatory disease is selected from systemic lupus erythematosus (SLE), rheumatoid arthritis, multiple sclerosis (MS), and Sjögren's syndrome. 